Radially tensioned wound or skin treatment devices and methods

ABSTRACT

Devices, kits and methods described herein may be for treatment to skin, including but not limited to wound healing, the treatment, amelioration, and/or prevention of scars or keloids. An applicator and/or tensioning device may be used to apply a dressing to a subject. The applicator and/or tensioning device applies and/or maintains a strain in an elastic dressing, wherein at least some of the strain is out-of-plane or at a non-orthogonal, non-parallel and non-aligned orientation to other strains in the dressing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/789,512 filed Mar. 7, 2013, which is a continuation of InternationalApplication Ser. No. PCT/US13/25449, filed Feb. 8, 2013. which claimsbenefit to U.S. Provisional Application Ser. No. 61/596,708, filed onFeb. 8, 2012, which are hereby incorporated by reference in theirentirety. This application is related to U.S. patent application Ser.No. 12/854,859, filed on Aug. 11, 2010 and U.S. patent application Ser.No. 13/345,524, filed Jan. 6, 2012, which are each hereby incorporatedby reference in its entirety.

BACKGROUND

Scar formation in response to cutaneous injury is part of the naturalwound healing process. Wound healing is a lengthy and continuousprocess, although it is typically recognized as occurring in stages. Theprocess begins immediately after injury, with an inflammatory stage.During this stage, which typically lasts from two days to one week(depending on the wound), damaged tissues and foreign matter are removedfrom the wound. The proliferative stage occurs at a time after theinflammatory stage and is characterized by fibroblast proliferation andcollagen and proteoglycan production. It is during the proliferativestage that the extracellular matrix is synthesized in order to providestructural integrity to the wound. The proliferative stage usually lastsabout four days to several weeks, depending on the nature of the wound,and it is during this stage when hypertrophic scars usually form. Thelast stage is called the remodeling stage. During the remodeling stage,the previously constructed and randomly organized matrix is remodeledinto an organized structure that is highly cross-linked and aligned toincrease mechanical strength.

While the histological features characterizing hypertrophic scars havebeen well documented, the underlying pathophysiology is not well known.Hypertrophic scars are a side effect of excessive wound healing, andgenerally result in the overproduction of cells, collagen, andproteoglycans. Typically, these scars are raised and are characterizedby the random distribution of tissue bundles. The appearance (i.e.,size, shape, and color) of these scars varies depending on the part ofthe body in which they form, and the underlying ethnicity of the personaffected. Hypertrophic scars are very common, and may occur followingany full thickness injury to the skin. Recently, it has been shown inU.S. Patent Application Publication 2006/0037091 (U.S. patentapplication Ser. No. 11/135,992 entitled “Method for ProducingHypertrophic Scarring Animal Model for Identification of Agents forPrevention and Treatment of Human Hypertrophic Scarring,” filed May 24,2005) which is hereby incorporated by reference in its entirety, thatmechanical stress may increase hypertrophic scarring in a murine model.

Keloids are typically characterized as tumors consisting of highlyhyperplastic masses that occur in the dermis and adjacent subcutaneoustissue in susceptible individuals, most commonly following trauma.Keloids are often more severe than hypertrophic scars, since they tendto invade normal adjacent tissue, while hypertrophic scars tend toremain confined within the original scar border.

BRIEF SUMMARY

Devices, kits and methods described herein may be for treatment of asubject at a skin site including without limitation for wound treatmentor the treatment, amelioration, or prevention of scars and/or keloids,by manipulating mechanical or physical properties of skin or byshielding skin from stresses, and/or by controllably stressing orstraining the epidermis and layers of dermal tissue at or near a skinsite, i.e., at or adjacent a wound or a treatment site of a subject'sskin. According to variations, manipulating mechanical or physicalproperties may thereby modulate tensile or compressive stress at theskin site. The stress at the skin site may be reduced to levels belowthat experienced by normal skin and tissue. The stress at the skin sitemay be increased to levels above that experienced by normal skin andtissue. The stress or strain may be applied to surrounding tissue inone, two, or more directions to manipulate endogenous or exogenousstress at the skin site in one, two or more directions. According tovariations, devices and methods described herein may reduce or otherwisemanipulate the stress experienced by skin and/or a wound and surroundingtissues in order to treat a subject. The devices may also assist inpreventing or reducing the incidence of wound dehiscence.

According to the devices, kits and methods described herein, a skintreatment device, skin device, wound treatment device, scar or keloidtreatment device, scar or keloid amelioration or prevention device,bandage, or dressing may be provided that may be applied, attached to orcoupled to one or more layers of the skin or tissue of a subject(hereinafter referred to as “dressing”, “skin device” or “skin treatmentdevice”).

In addition to amelioration of scar formation, other uses for such skintreatment device may or may not include without limitation, for example,treating skin related conditions such as acne, blemishes, rosacea,warts, rashes (including but not limited to erythematous, macular,papular and/or bullous conditions), psoriasis, skinirritation/sensitivity, allodynia, telangiectasia, port wine stains andother arterio-venous malformations, and ectopic dermatitis; treating orimproving existing scars, wrinkles, stretch marks, loose or sagging skinor other skin irregularities; lifting, pinning, holding, moving skin forvarious purposes such as during pre-operative preparation, duringsurgical procedures for example as a low-profile tissue retractor, tostabilize blood vessels during needle or catheter insertion,postoperatively, pre or post operatively for pre-treating orpreconditioning skin for example, prior to scar revision, woundincision, body contouring, in mastectomy skin expansion, aesthetic skintreatment or resurfacing whether topical or subdermal, whether or notusing an energy modality such as, for example, microwave,radio-frequency ablation, high-intensity focused ultrasound, laser,Infrared, incoherent light, during weight loss, or for aestheticpurposes; hair removal or hair loss; treating and/or closing skininjuries for example, incisions, wounds, chronic wounds, bed sores,ulcers (including venous stasis ulcers), preventing or reducing theincidence of wound dehiscence, diabetic skin or wound conditions, burnhealing and/or relief; acting as an occlusive or negative-pressure wounddressing; protecting incisions or wounds, e.g. prevention of splittingor opening, protecting newborn belly buttons after cutting umbilicalcord. Such treatments may also be used to treat skin grafts (includingsplit-thickness and full-thickness grafts, xenografts, cadaveric graft,autologous grafts), skin flaps and skin substitutes, with or without theuse of biomaterials or biodressings, either on top and/or below thegraft/flap/substitute, or otherwise in the treatment site. Examples ofsuch materials may include ALLODERM® (LifeCell Corp., Branchburg, N.J.),OASIS® (Healthpoint Ltd., Fort Worth, Tex.), INTEGRA® DermalRegeneration Template (Integra Life Sciences Holding Co., SouthPlainfield, N.J.), BIOBRANE® and BIOBRANE-L (Bertek Pharmaceuticals,Sugarland Tex.), APLIGRAF® (Organogenesis Inc., Canton, Mass.), EPICEL®(Genzyme Biosurgery, Cambridge, Mass.), CELADERM™ (Celadon Science LLC,Hyattsville, Md.), TRANSCYTE® and DERMAGRAFT® (Advanced BioHealing Inc.,Westport, Conn.), EZ (Brennan Medical Inc., St. Paul, Min.), LASERSKIN®(Fidia Advanced Biopolymers, Italy), ORCEL® (FortiCell Bioscience Inc.,Englewood Cliffs, N.J.), and the like. Such treatments may include useof a drug or other therapeutic agent that may be applied to the skinwith such device. The agents may include but are not limited toantibiotics, anti-fungals, immune modulators including corticosteroidsand non-steroidal immune modulators. The agents may be provided in anyof a variety of formulations, including but not limited powders, gels,lotions, creams, pastes, suspensions, etc. The devices may also be usedfor purposes of delivering a drug to the skin or through the skin, forexample by stretching the skin and applying a drug thereto. Differentconfigurations of the device may be amenable to the size or geometry ofdifferent body regions. The treatments may be applied to regions of anyshape (e.g. linear, curved, stellate), size or depth, and to one or moreregions of the body, including but not limited to the scalp, forehead,face e.g. nose, eyelid, cheeks, lips, chin), ears, neck, shoulder, upperarm, lower arm, palm, dorsum of the hand, fingers, nailbed, axilla,chest, nipple, areola, back, abdomen, inguinal region, buttocks,perineal region, labia, penis, scrotum, thigh, lower leg, plantarsurface of the foot, dorsal surface of the foot, and/or toes. Suchdevices may also be referred to herein as a “dressing”, “skin device” or“skin treatment device”.

In some situations, an immediate, quick or simple application of adressing may be desired. Devices, kits and methods described herein maybe for the preparation and/or application of a dressing to the skin andthe separation of the applicator, tensioning device or dressing carrier,support or base from the skin device.

The devices, kits or methods described herein may include a carrier,support, base, applicator or tensioning device, each of which may:contain, hold, carry or support a dressing at least temporarily; may beused to prepare a dressing for application; may be used to deliver,orient or apply a dressing; may be used to maintain a dressing in astressed or strained configuration; may be used to stress or strain adressing; may be used to separate the dressing from the carrier,support, base, applicator or tensioning device and/or may be used duringor after application of a dressing to provide additional treatment to awound, incision or other treatment location; and/or may be used to applypressure to a wound, incision or other treatment location. According tosome variations, an applicator may provide structural support for adressing while or after an adhesive liner is released. According to somevariations, the assembly may be constructed to avoid folding or bendingof the dressing to the extent that the adhesive on the dressing sticksto itself. For example, when some variations of the dressing are held orsupported at one point or along one edge of the dressing in a cantileverconfiguration, the dressings will not bow, laterally deform, orotherwise deform out of plane, under their own mass or configuration.

Devices, kits and methods described herein may be for the treatment,amelioration, or prevention of scars and/or keloids by creating and/ormaintaining a pre-determined strain in an elastic skin treatment devicethat is then affixed to the skin surface using skin adhesives totransfer a generally planar (e.g. compressive) force from the bandage tothe skin surface.

In some variations, a dressing is provided, comprising an elastic sheetstructure (e.g., a comprising a silicone polyurethane, TPE(thermoplastic elastomers), synthetic rubber or co-polyester material)comprising an upper surface, a lower surface, a first edge and a secondedge opposite the first edge, and one or more adhesive regions. Thedressing may further comprise a first release liner releasably attachedto the adhesive region or regions. The adhesive region(s) may comprise apressure sensitive adhesive. The dressing may be tapered or otherwiseshaped to reduce skin tension at the edges. The dressing may havemodified, reduced or no adhesive near its edges to reduce skin tensionat the edges. Portions of the dressing may be unstrained and may therebyreduce strain in certain areas of the skin Where the dressing isapplied. In some specific examples, the unstrained area or areas arefound between the edges of the dressing and the strained area(s). Insome further examples, the unstrained areas are limited to this area andare not found, during application or use, between the strained areas ofa single dressing, in use. In still further examples, the unstrainedareas are limited to areas along the edges of a dressing that intersectthe strain axis of the strained area(s), but not to areas along theedges of the dressing that are generally parallel to the strain axis.

A dressing carrier, dressing support, dressing base, applicator and/ortensioning device may be provided. The dressing carrier, dressingsupport, dressing base, applicator and/or tensioning device may beconfigured to stress and/or strain a dressing prior to application to asubject. A device may be used to strain and/or maintain a strain on adressing. The device may further comprise a releasable lockingmechanism, attachment mechanism or adhesive, configured to maintain themember or mechanism in a strained configuration.

In some situations, application of a compressive force to a wound isdesirable to reduce bleeding. According to some variations, the carrier,support, base, applicator or tensioning device described herein may befurther used to help reduce bleeding, e.g., by allowing application of acompressive force using the device while or after the dressing isapplied. A coagulative additive may also be provided on a dressing.

According to some variations, a dressing assembly comprises: a basestructure having an inner surface; a cover structure having an opposingsurface, wherein the base structure is movably coupled to the coverstructure; and a dressing comprising a first surface configured to heapplied to a wound or skin of a subject, and a back surface, wherein atleast a portion of the back surface is removably coupled to the innersurface of the base structure; and wherein the cover structure isconfigured to move from a first position where the opposing surfaceinterfaces with and is substantially parallel to the first surface tothe dressing to a second position where the opposing surface isseparated from the first surface of the dressing. According tovariations, the first surface of the dressing comprises an adhesiveregion. According to variations the first surface of the dressingcomprises an adhesive backing interfacing an adhesive region on thedressing. According to variations, the opposing surface of the coverstructure comprises an adhesive backing covering the adhesive regionwhen the cover structure is in the first position and separated from theadhesive region when the cover structure is in the second position.According to variations, the dressing comprises an elastic material.According to variations, the dressing comprises a first attachmentregion coupled to the inner surface of the base structure and a secondattachment region coupled to the opposing surface of the coverstructure, wherein the cover and base are configured to exert astraining force to strain the dressing when the cover is moved from thefirst position to the second position. According to variations, atensioning structure is configured to exert the straining force on thedressing. According to variations, the tensioning structure comprises: afirst structure configured to couple the dressing at the firstattachment region to the inner surface of the base structure; and asecond structure configured to couple the dressing at the secondattachment region to the opposing surface of the cover; wherein thetensioning structure is configured to exert the straining force to thedressing between the first attachment region and the second attachmentregion when the cover structure is moved with respect to the basestructure from the first position to the second position. According tosome variations, the dressing has a first width when the cover is in thefirst position and a second width or radius when the cover is in thesecond position, wherein the second width or radius is greater than thefirst width or radius. According to variations, the second width orradius is at least 20% greater than the first width or radius. Accordingto variations, the second width or radius is at least 40% great than thefirst width or radius. According to variations, the base structurecomprise at least one relatively rigid element and at least onerelatively flexible element, wherein the relatively rigid element issufficiently rigid to support the dressing when the straining force isapplied in a first direction; and wherein the relatively flexibleelement permits the base structure to flex in a second direction.According to variations, the at least one relatively rigid elementcomprises a plurality of flexible coupled, relatively rigid elements.According to variations, the cover structure comprises at least onerelatively rigid element and at least one relatively flexible element.According to variations, a release device is configured to release thedressing from the base structure after the dressing is applied to awound or skin of a subject. According to some variations, base structureis pivotably coupled to the cover structure.

Described herein is a dressing system that may comprise a dressingcomprising a first edge and a second edge, where the second edge mayhave an orientation that is non-parallel and non-orthogonal to the firstedge when the dressing is in an unstrained state, and a first facecomprising an adhesive, and a frame removably attached to the dressingand supporting the first edge and the second edge of the dressing, theframe comprising an outer edge, an inner edge, and an opening surroundedby the inner edge. In some variations, the frame may be coupled to asecond face of the dressing opposite of the first face. The dressing maycomprise a circular or oval dressing. In some variations, the dressingmay comprise a release region configured to separate the dressing fromthe frame. In some variations, the release region may comprise at leastone of a scored region, a perforated region, or comprises an embeddedpull line. Additionally or alternatively, the release region maycomprise a pull tab coupled to the release region. The first edge of thedressing may comprise an arcuate edge with a first radius of curvature.In some variations, the second edge of the dressing may comprise anarcuate edge with a second radius of curvature. The second radius ofcurvature may be different from the first radius of curvature.

A dressing system may further comprise a straining structure configuredto be pushed through the opening of the frame and to strain thedressing. The frame may be configured to be adhered to the strainingstructure. In some variations, the frame forms a mechanical interfitwith the base. In some variations, the straining structure may comprisea base and raised protrusion. The raised protrusion may comprise a sidewall that is orthogonal to the base. In some variations, the raisedprotrusion may comprise a side wall that forms an open angle with thebase that is greater than 90 degrees, while in other variations, theraised protrusion may comprise a side wall that forms an open angle withthe base that is less than 90 degrees. The straining structure maycomprise a distal face configured to push against the second face of thedressing. The distal face of the straining structure may comprise ageneral shape that is similar to at least one of the dressing, theopening of the frame, the base or the shape of the side wall at anintersection with the base.

The straining structure and the frame may be configured to apply agenerally apply uniform straining forces to the dressing that areorthogonal to the first and second edges of the dressing.

in some variations, the straining structure and the frame may beconfigured to apply a first straining force to the dressing that isorthogonal to the first edge of the dressing and a second strainingforce to the dressing that is orthogonal to the second edge of thedressing, the second straining force of the dressing is higher thanstraining force to the dressing that is orthogonal to a third and fourthedge of the dressing that are located to each side of the second edge.

Any of the dressing systems described herein may further comprise acutting structure configured to cut the dressing from the frame.

Another variation of a dressing system may comprise a dressing with anunstrained circular or oval shape and a strained circular or oval shapewherein the strain on a first transverse dimension is the same as thestrain on a second transverse dimension that is not aligned, parallel ororthogonal to the first transverse dimension.

Another variation of a dressing system may comprise a strainingstructure, a dressing and a frame configured to releasably retain anelastic dressing, where the straining structure and the frame may beconfigured to apply a first straining force to the dressing that isorthogonal to the first edge of the dressing and a second strainingforce to the dressing that is orthogonal to the second edge of thedressing, and where the second straining force of the dressing may behigher than straining force to the dressing that is orthogonal to athird and fourth edge of the dressing that are located to each side ofthe second edge.

Also described herein are methods of straining a dressing. One variationof a method of straining a dressing may comprise straining a firstdressing region along a first axis located in a first plane, straining asecond dressing region along a second axis located in a second planedifferent from the first plane, wherein the second dressing is coupledto the first dressing region, applying the first dressing region to atreatment site, and releasing at least some strain from the firstdressing region. Some methods of straining a dressing may furthercomprise separating a third dressing region from the second dressingregion to relieve at least some strain the first dressing region.Optionally, the second dressing region may enclose the first dressingregion. Optionally, the third dressing region may enclose the seconddressing region. In some methods, releasing at least some strain in thefirst dressing region may release substantially all of the strain in thesecond dressing region

Another method of straining a dressing may comprise straining a dressingwith a uniform set of strain forces, where a first force with anorientation that is orthogonal to a first edge of the dressing and asecond force that is orthogonal to a second edge and equal to the firstforce and has an orientation that is non-aligned, non-parallel andnon-orthogonal to the first edge, applying the strained dressing to atreatment site, and relieving the strain in the dressing to apply acompressive force to the treatment site. The dressing may be a circularor oval dressing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic superior view of one variation of a woundtreatment device;

FIG. 1B is a schematic side elevational view of the wound treatmentdevice in FIG. 1A;

FIGS. 2A and 2B are schematic superior and side elevational views of thewound treatment in FIGS. 1A and 1B, respectively, with release liners;FIG. 2C is a superior component view of the release liners in FIGS. 2Aand 2B;

FIG. 3A is a perspective view of a wound treatment applicator in a baseconfiguration; FIGS. 3B to 3D are side elevational, superior andinferior views of the applicator in FIG. 3A;

FIGS. 4A to 4D are perspective, side elevational, superior and inferiorviews of the applicator in FIGS. 3A to 3D in a locked configuration;

FIGS. 5A and 5B are schematic perspective and side elevational views ofthe applicator in FIGS. 4A and 4B loaded with a wound treatment device;

FIGS. 6A to 6C are superior, cross sectional and side elevational viewsof a dressing comprising pockets.

FIGS. 7A to 7C are cross sectional views of alternate embodiments of adressing comprising pockets.

FIGS. 8A and 8B are superior and cross sectional views of anotherdressing comprising T-tag attachment structures.

FIGS. 9A and 9B are superior and cross sectional views of anotherdressing comprising eyelet attachment structures,

FIGS. 10A to 10C are superior, cross sectional and side elevationalviews of another dressing comprising a hook-and-loop type of attachmentstructure.

FIG. 11 depicts an applicator with corresponding hook-and-loop type ofattachment structures configured for use with the dressing in FIGS. 10Ato 10C.

FIG. 12 depicts another applicator with corresponding hook-and-loop typeof attachment structures configured for use with the dressing in FIGS.10A to 10C.

FIG. 13A is a superior view of an applicator in an unstrainedconfiguration; FIG. 13B is a superior view of the applicator of FIG. 13Ain a strained configuration; FIG. 13C is an inferior perspective view ofthe applicator of FIG. 134 in an unstrained configuration; FIG. 13D isan inferior perspective view of the applicator of FIG. 13A in a strainedconfiguration; FIG. 13E is a perspective view of the applicator withintegrated stamper, in an unstrained configuration; FIG. 13F is aperspective view of the applicator of FIG. 13E in a strainedconfiguration; FIG. 13G is a side view of the applicator of FIG. 13E inan unstrained configuration; FIG. 13H is a side view of the applicatorof FIG. 13E in a strained configuration; and FIG. 13I is a side view ofthe applicator of FIG. 13E in a strained configuration with a deployedstamper.

FIG. 14A is a schematic of one variation of a circular dressing. FIG.14B is a schematic of one variation of a rectangular dressing.

FIG. 15A is an exploded perspective view in a first direction of atensioning device and dressing assembly.

FIG. 15B is an exploded perspective view in an opposite direction of thetensioning device and dressing assembly of FIG. 15A.

FIG. 15C is a cross-sectional view of a strain plunger of the tensioningdevice and an assembled dressing assembly and frame of FIG. 15A alongthe lines A-A.

FIG. 15D is a detailed view of section B of FIG. 15C.

FIG. 15E is a cross-sectional view of a tensioning member straining adressing of the dressing assembly of the dressing assembly andtensioning device of FIG. 18A.

FIG. 15F illustrates a strain plunger.

FIG. 15G illustrates a strain plunger.

FIG. 15H illustrates an attachment ring.

FIGS. 15I to 15M illustrate various exemplary embodiments of frame withattached dressings, from the dressing side of the frame.

FIG. 16A is an exploded perspective view in a first direction of atensioning device and dressing assembly.

FIG. 16B is an exploded perspective view in an opposite direction of thetensioning device and dressing assembly of FIG. 16A.

FIG. 16C is a plan view of an open side of the frame of FIG. 16A coupledto the dressing assembly of FIG. 16A from the open side of the device.

FIG. 16D is a close-up cross-sectional view of a strain plunger of thetensioning device and an assembled dressing assembly and frame of FIG.16C just prior to straining.

FIG. 16E is a detailed view of section B of FIG. 16D.

FIG. 16F is a cross sectional view of FIG. 16C along lines B-B.

FIG. 16G schematically depicts the dressing at a treatment site andafter the applicator has been removed.

FIG. 16H is a cross section along lines A-A of the straining structureof FIG. 16A.

FIG. 16I is an enlarged view of Section B of FIG. 16H.

FIG. 16J is a schematic cross section of a variation of a strainingstructure.

FIG. 16K is a perspective view of a variation of a straining structure.

FIG. 17 illustrates a subject with non-linear incisions.

FIG. 18 illustrates a customized dressing.

DETAILED DESCRIPTION

Previous attempts to treat scars and keloids have included surgery,silicone dressings, steroids, x-ray irradiation, and cryotherapy. Eachof these techniques has disadvantages. Perhaps the biggest disadvantageis that none of them effectively prevent or ameliorate the formation ofscars or keloids in the first instance. That is, these techniques haveprimarily been used to treat scars after they are already wellestablished.

Unloading of exogenous and/or endogenous stress in the vicinity of thewound may ameliorate the formation of scars, hypertrophic scars, orkeloids. The mechanical environment of an injury may be an importantfactor in tissue response to that injury. The mechanical environmentincludes exogenous stress (i.e., physiological stress which includesstress transferred to the wound via muscle action or physical bodymovement) and endogenous stress (i.e., dermal stress originating fromthe physical properties of the skin itself, including stress induced atthe wound site due to swelling or contraction of the skin). The devices,dressings, kits and methods described herein may control or regulate themechanical environment of a skin including but not limited to themechanical environment of a wound. The devices, dressings, kits andmethods described herein may also control or regulate the mechanicalenvironment to ameliorate scar and/or keloid formation. The mechanicalenvironment of skin may include stress, strain, or any combination ofstress and strain. The control of a wound's mechanical environment maybe active or passive, dynamic (e.g., by applying an oscillating stress)or static. The stresses and strains acting on the wound may involve thelayers of the skin, such as the outer stratum cornewn, the epidermis anddermis, as well as the underlying connective tissue layers, such as thesubcutaneous fat.

Devices and methods described here may shield a wound from itsmechanical environment, The term “shield” is meant to encompass theunloading of stress experienced by the wound as well as providing aphysical barrier against contact, contaminants, and the like. Thedevices and methods described here may shield a wound by unloading thewound and surrounding tissues from endogenous stress and/or exogenousstress. Thus, devices and methods described here may reduce the stressexperienced by a wound and surrounding tissues to a lower level thanthat experienced by normal skin and tissue. Unloading of exogenousand/or endogenous stress in the vicinity of the wound may ameliorate theformation of scars, hypertrophic scars, or keloids.

A cell's external mechanical environment may trigger biologicalresponses inside the cells and change cell behavior. Cells can sense andrespond to changes in their mechanical environment using integrin, anintegral membrane protein in the plasma membrane of cells, andintracellular pathways. The intracellular pathways are initiated byreceptors attached to cell membranes and the cell membrane that cansense mechanical forces. For example, mechanical forces can inducesecretion of cytokines, chemokines, growth factors, and otherbiologically active compounds that can increase or trigger theinflammatory response. Such secretions can act in the cells that secretethem (intracrine), on the cells that secrete them (autocrine), on cellssurrounding the cells that secrete them (paracrine), or act at adistance from the point of secretion (endocrine). Intracrineinterference can alter cell signaling, which can in turn alter cellbehavior and biology including the recruitment of cells to the wound,proliferation of cells at the wound, and cell death in the wound. Inaddition, the extracellular matrix may be affected.

As noted above, the wound healing process may be characterized in threestages: early inflammatory phase, the proliferative phase, andremodeling. The inflammatory phase occurs immediately after injury andtypically lasts about two days to one week. Blood clotting takes placeto halt blood loss and factors are released to attract cells that canremove debris, bacteria and damaged tissue from the wound. In addition,factors are released to initiate the proliferative phase of woundhealing. In the proliferative phase, which lasts about four days toseveral weeks, fibroblasts grow and build a new extracellular matrix bysecreting collagen and proteoglycans. At the end of the proliferativephase, fibroblasts can act to contract the wound further. In theremodeling phase, randomly oriented collagen is organized andcrosslinked along skin tension lines. Cells that are no longer neededcan undergo apoptosis. The remodeling phase may continue for many weeksor months, or indefinitely after injury. Scars typically reach about75-80% of normal skin breaking strength about 6-8 weeks after injury. Ingeneral, scars typically have a triangular cross-section. That is, ascar is usually smallest in volume near the skin surface (i.e., stratumcorneum and epidermis) and increases in volume as it progresses into thedeeper layers of the dermis.

There are three common possible outcomes to a wound healing process.First, a normal scar can result. Second, a pathologic increase in scarformation can result, such as formation of a hypertrophic scar or akeloid. Third, the wound may not heal completely and become a chronicwound or ulcer. The devices, kits and methods described herein canameliorate the formation of any type of scar. In addition, the devices,kits and methods described here can be adapted for a variety of woundsizes, and for different thicknesses of skin, e.g., the devices may beconfigured for use in different areas of the body. In addition, thedevices, kits and methods described here can be adapted to amelioratescar formation in any type of skin, e.g., body location, age, race, orcondition.

Without wishing to be bound by any particular theory, we believe thatmechanical strain acting on a wound or incision early in theproliferative phase of the wound healing process may inhibit cellularapoptosis, leading to a significant accumulation of cells and matrix,and hence increased scarring or the production of hypertrophic scars.Given the underlying similarities between hypertrophic scars and keloidswith respect to excessive matrix formation, we believe that the devicesand methods described herein may also be useful in preventing andtreating keloids by offloading or neutralizing at least some of thestrain that may be acting on the wound or incision. This tensile strainmay be exogenous and/or endogenous strain, and may include but is notlimited to the strain from the intrinsic tensile forces found in normalintact skin tissue.

Devices, kits and methods described herein may treat skin at a skin site(“skin treatment device”), including without limitation, to amelioratethe formation of scars at wound sites by controllably stressing orstraining the epidermis and deeper layers of dermal tissue at or near askin site, i.e., at or adjacent a wound or treatment site of a subject'sskin, thereby reducing tensile or compressive stress at the skin site.The stress at the skin site may be reduced to levels below thatexperienced by normal skin and tissue. The stress or strain may beapplied to surrounding tissue in one, two, or more directions to reduceendogenous or exogenous stress at the skin site in one, two or moredirections. Thus, devices and methods described herein may reduce thestress experienced by skin and/or a wound and surrounding tissues inorder to treat a subject. The device may also assist in preventing orreducing the incidence of wound dehiscence.

Devices kits and methods described herein may be for the preparationand/or application of a dressing. Such preparation may include but isnot limited to, for example, removal of an adhesive liner, straining ortensioning a dressing, orienting a dressing for application and/orapplying a medicament or other material to a portion of the dressingprior to application.

According to some variations, the packaging dressing carrier, support,base tensioning device or applicator tensioning device and/or applicatorprovide a release mechanism to separate the applied dressing from thepackaging and/or applicator after the dressing is applied to the skin.According to a variation, a dressing may be prestrained and coupled to adressing carrier, support, base tensioning device or applicator, forexample as set forth in U.S. Provisional Application Ser. No. 61/512,340filed on Jul. 17, 2011 and incorporated in its entirety herein byreference. One or more dressing releases described herein may be usedwith a dressing carrier, support, base tensioning device or applicator.

According to some variations, the tensioning device, dressing carrier,support, base or applicator may further comprise an opening, a window,or a clear or semi-opaque portion through which a wound, incision orother location may be visualized as the dressing is applied to the skin.According to some variations, the window guides the application of adressing so that there is an optimal or desired distance between thewound and the edges of the dressing and/or so that the dressing is in anoptimal location for unloading skin stresses.

According to some variations the applicator, tensioning device, orcarrier, suppo or base may provide varied or variable flexibility toallow the dressing to be shaped when applied to various body locationsor contours.

According to some variations, the applicator may be further used to helpreduce bleeding, e.g., by allowing application of a compressive forceusing a support structure while or after the device is applied. One ormore hemostatic or coagulative agents may be applied to, or otherwiseintegrated with dressing to help reduce bleeding. Potential agentsinclude chitosan, calcium-loaded zeolite, microfibrillar collagen,cellulose, anhydrous aluminum sulfate, silver nitrate, potassium alum,titanium oxide, fibrinogen, epinephrine, calcium alginate, poly-N-acetylglucosamine, thrombin, coagulation factor(s) (e.g. II, VII, VII, X,XIII, Von Willebrand factor), procoagulants (e.g. propyl gallate),antitibrinolytics (e.g. epsilon aminocaproic acid), and the like. Insome variations, the agents may be freeze-dried and integrated into thedressing and activated upon contact with blood or other fluid. In somefurther variations, an activating agent may be applied to the dressingor the treatment site before the dressing is used on the subject. Instill other examples, the hemostatic agent may be applied separately anddirectly to the wound before application of the dressing, or afterapplication to the dressing via a catheter or tube. The devices may alsocomprise one or more other active agents that may be useful in aiding insome aspect of the wound healing process. For example, the active agentmay be a pharmaceutical compound, a protein (e.g., a growth factor), avitamin (e.g., vitamin E), or combinations thereof. A further example ofsuch medicament may include, but is not limited to various antibiotics(including but not limited to cephalosporins, bactitracin, polyxyxin Bsulfate, neomycin, polysporin), antiseptics (such as iodine solutions,silver sulfadiazine, chlorhexidine), antifungals (such as nystatin),antiproliferative agents (sirolirnus, tacrolimus, zotarolimus, biolimus,paclitaxel), grow factors (such as VEGF) and other treatments (e.g.botulism toxin. Of course, the devices may comprise more than onemedicament or agent, and the devices may deliver one or more medicamentsor agents.

According to some variations, the applicator may also be used to straina dressing prior to application to provide a dressing configured toameliorate scar or keloid formation.

Devices are described here that may be used for ameliorating theformation of scars and/or keloids at a skin or wound site. The scars maybe any type of scar, e.g., a normal scar, a hypertrophic scar, etc. ingeneral, the devices may be configured to be removably secured to a skinsurface near a wound. The devices may shield the skin or wound fromendogenous stress and/or exogenous stress. In some variations, thedevices may shield the skin or wound from endogenous stress withoutaffecting exogenous stress on the skin or wound, e.g., devices thatmodify the elastic properties of the skin, etc. In other variations, thedevices may shield the skin or wound from exogenous stress withoutaffecting endogenous stress on the wound. Such variations may includesituations where the musculature and surrounding skin or wound tissuehas been paralyzed, e.g., through the use of botulinum toxin or thelike. In still other variations, the devices shield the skin or woundfrom both endogenous and exogenous stress.

The devices or dressings described herein may treat skin at a skin siteincluding without limitation to ameliorate the formation of scars atwound sites by controllably stressing or straining the epidermis anddeeper layers of dermal tissue at or near a skin site, thereby reducingtensile or compressive stress at the skin site itself. The stress at theskin site may be reduced to levels below that experienced by normal skinand tissue. The stress or strain may be applied to surrounding tissue inone, two, or three or more directions to reduce endogenous or exogenousstress at the skin site in one, two or three or more directions. Thephysical characteristics of the dressing and/or the method of applyingthe dressing may also be further configured to resist or reduce the rateof skin stripping or tension blistering from the application of strainto the incision site. For example, the stretching of the adhesiveregions when applied to the skin surface may result in an increasedtissue density under the adhesive region. This may be the result ofgenerally planar, tangential or parallel compression of skin tissue thatis directly attached to that adhesive region, resulting from therelaxation of the adhesive region. In some examples, this tissuecompression may reduce the risk of tissue stripping and/or blistering ofskin in direct contact with the adhesive, in contrast to bandage“strapping” where one end of a bandage is adhered to the skin and thentensioned or pulled across a wound before the other end is attached tothe skin on the opposite side of the wound. Bandage “strapping”, whilegenerating tension in the bandage during the application, maysimultaneously generate a relatively high tissue strain at the firstadhesion site. This high tissue strain then decreases when the bandageis attached to the skin at a second adhesion site as the high peakstresses are redistributed along the skin under the bandage. Incontrast, when a pre-strained bandage is applied to the skin, little ifany strain may be transferred or generated in the skin as the adhesiveregions are applied to the desired locations. When the pre-strainedbandage is permitted to relax, however, the strain (or peak strain) inthe skin may be increased. Thus, with a pre-strained bandage, temporaryhigh tissue strain may be avoided or otherwise reduced during theapplication procedure. In other variations, however, the dressing mayalso be applied to the skin by strapping, or by a combination ofpre-straining and strapping.

The dressing may comprise an elastic member, such as a sheet of elasticmaterial. The elastic material of the dressing may comprise a singlelayer of material or multiple layers of the same or different materials.The material may have any of a variety of configurations, including asolid, foam, lattice, or woven configuration. The elastic material maybe a biocompatible polymer, e.g., silicone, polyurethane, TPE(thermoplastic elastomers), synthetic rubber or co-polyester material.The thickness of polymer sheets may be selected to provide the dressingswith sufficient load carrying capacity to achieve desired recoverablestrains, and to prevent undesired amounts of creep deformation of thedressings over time. In some variations, the thickness across dressingsis not uniform, e.g., the thickness across the dressing may be varied tochange the stiffness, the load carrying capacity, or recovery strains inselected orientations and/or locations. The elastic material of theexemplary dressing may have a thickness in the range of about 50 micronsto 1 mm or more, about 100 microns to about 500 microns, about 120microns to about 300 microns, or in some variations about 200 microns toabout 260 microns. The exemplary dressings have an edge thickness ofabout 500 microns or less, 400 microns or less, or about 300 microns orless may exhibit less risk of skin separation from inadvertent liftingwhen inadvertently brushed against clothing or objects. In somevariations, the dressings are tapered near the edges to reducethickness. A tapered edge may also ameliorate peak tensile forces actingon skin tissue adjacent to the adhesive edges of the dressing. This mayor may not reduce the risk of skin blistering or other tension-relatedskin trauma. In other variations, the edges of the dressing may bethicker than the middle of the dressing. It is hypothesized that in someconfigurations, a thicker dressing edge may provide a relative inwardshift of the location of the peak tensile forces acting near thedressing edge, compared to dressings of uniform thickness. The elasticmaterial may have a load per width of at least 0.35 Newtons per mm at anengineering strain of 60% or a load per width of at least 0.25 Newtonsper mm at an engineering strain of 45%. The elastic material may have aload per width of no greater than about 2 Newtons per mm at theengineering strain of about 45% to 60%, about 1 Newtons per mm at theengineering strain of about 45% to 60%, about 0.7 Newtons per mm at theengineering strain of about 45% to 60%, or no greater than about 0.5Newtons per mm at the engineering strain of about 45% to 60%. The systemelastic material may have a load per width that does not decrease froman engineering strain of 0% to 60%, a load per width plot that increaseslinearly from an engineering strain of 0% to 60%, or a load per widthplot that is not convex from an engineering strain of 0% to 60%. Theelastic material may comprise an adhesive configured to maintain asubstantially constant stress in the range of 200 kPa to about 500 kPafor at least 8 hours when strained to an engineering strain of about 20%to 30% and attached to a surface.

The elastic material may comprise an adhesive configured to maintain asubstantially constant stress in the range of 200 kPa to about 400 kPafor at least 8 hours when strained to an engineering strain of about 20%to 30% and attached to a surface. The substantially constant stress mayvary by less than 10% over at least 8 hours, or by less than 5% over atleast 8 hours.

Although the depicted dressings may have a generally rectangularconfiguration with a length and/or width of about 160 mm to about 60 mm,in other variations the dressing may have any of a variety of lengthsand widths, and may comprise any of a variety of other shapes. Also, thecorners of the dressing may be squared or rounded, for example. Thelengths and/or widths of an exemplary dressing may be in the range ofabout 5 mm to about 1 meter or more, in some variations about 20 mm toabout 500 mm, and in other variations about 30 mm to about 50 nun, andin still other variations about 50 mm to about 100 mm. In somevariations, the ratio of the maximum dimension of the dressing (e.g. itslength) to an orthogonal dimension to the maximum dimension(e.g. width),excluding the minimum dimension of the dressing (e.g. the thickness),may be in the range of about 1:3, about 1:2, about 1:1, about 2:1, about3:1, about 4:1 about 5:1, about 6:1, about 7:1, about 8:1, about 9:1 orabout 10:1 or greater. In some variations, the strain axis of thedressing in use may be oriented with respect to the maximum dimension orto the orthogonal dimension to the maximum dimension. In somevariations, the final compressive stress and strain imposed onto theskin by the elastic material may be the result of the dynamicequilibrium between the tensile stress in the skin and the elasticmaterial of the dressing. The skin at the skin site typically comprisesan inherent tension that stretches incision site, whether or not anytissue was excised from the skin site. The elastic material and theadhesive region may be configured to be applied to a skin location sothat when the dressing is stretched to a particular tension and thenadhered to the incision site, tensile stress in the dressing istransferred to the incision site to compress the tissue directly underthe dressing along a tangential axis to the skin surface, the stress andstrain imposed onto the skin location has a net or resultant orientationor axis is also generally tangential or planar to the elastic materialand/or the outer surface of the skin location, with a similar axis tothe orientation or axis of the tensile stress in the dressing. Thetension in the dressing will relax to a tension level that maintainsequilibrium with increased tension in the skin adjacent to the dressing.The application of the dressing to the skin location may involve theplacement of the dressing without overlapping or being wrapped ontoitself, e.g. wherein only adjacent regions of the dressing areinterconnected and wherein non-adjacent regions of the dressing are notinterconnected. The actual amount of stress and strain imposed on theskin may vary, depending upon the particular person, skin location, thethickness or various mechanical characteristics of the skin layers (e.g.epidermis, dermis, or underlying connective tissues), and/or the degreeof pre-existing scarring, for example in some further variations, thewound treatment dressing may be selected or configured for use at aspecific body location, such as the scalp, forehead, cheek, neck, upperback, lower back, abdominal region, upper torso (including but notlimited to the breast folds), shoulder, upper arm, lower arm, palmregions, the dorsum of the hand, finger, thigh, lower leg, the dorsum orplantar surface of the foot, and/or toe. Where applicable, some bodyregions may be further delineated into anterior, posterior, medial,lateral, proximal and/or distal regions, e.g. the arms and legs.

The dressing may be configured to impose a skin strain in the range ofabout 10% to about 60% or more, in other configurations about 15% toabout 50%, and in still other configurations, about 20% to about 30% orabout 40%. To achieve the desired degree of skin strain, the dressingmay be configured to undergo elastic tensile strain in the range ofabout 20% to about 80% or more, sometimes about 30% to about 60%, andother times about 40% to about 50% or about 60%. The dressing maycomprise any of a variety of elastic materials, including but notlimited to silicones, styrenic block copolymers, natural rubbers,fluoroelastomers, peril uoroelastomers, polyether block amides,thermoplastic elastomers, thermoplastic polyurethane, polyisoprene,polybutadiene, and the like. The material of the exemplary dressing mayhave a Shore A durometer in the range of about 20 to about 90, about 30to about 80, about 50 to about 80. The exemplary dressing wasconstructed of MED 82-5010-05 by NUSIL TECHNOLOGY LLC (Carpinteria,Calif.). Other examples of suitable materials are described in U.S.application Ser. No. 11/888,978, which was previously incorporated byreference in its entirety.

When the dressing is applied to a skin location and allowed to at leastpartially recover to its base configuration, the recovery level orequilibrium level of strain in the dressing may be in the range of about4% to about 60% or more, in other configurations about 15% to about 50%,and in still other configurations, about 20% to about 30% or about 40%.The ratio between the initial engineering tensile strain placed onto thedressing before recovery and the resulting engineering compressivestrain in the skin may vary depending upon the skin type and location,but in some examples, may be about 2:1. In other examples, the ratio maybe in the range of about 4:1 to about 5:4, about 3:1 to about 5:3, orabout 5:2 to about 2:1. These skin strain characteristics may bedetermined with respect to a reference position of the body or bodypart, e.g. anatomical position, to facilitate reproducible measurements.The particular degree of strain may be characterized as either anengineering strain or a true strain, but may or may not be calculatedbased upon or converted from the other type of strain (e.g. the strainmay be based upon a 45% engineering strain that is converted to a truestrain).

In some further variations, one or more characteristics of the elasticmaterial may correspond to various features on the stress/strain curveof the material. For example, the engineering and true stress/straincurves for one specific example of the dressing comprises a materialthat exhibits an engineering stress of about 1.2 MPa at about 60%engineering strain, but in other examples, the engineering stress may bein the range of about 900 KPa to about 3.5 MPa, about 1 MPa to about 2.2MPa, about 1 MPa to about 2 MPa, about 1.1 MPa to about 1.8 MPa, about1.1 MPa to about 1.5 MPa, about 1.2 MPa to about 1.4 MPa. When unloadingor relieving stress from the dressing, the material may be configuredwith an engineering stress of about 380 KPa at about 40% engineeringstrain, but in other examples, the engineering stress during unloadingof the material to about a 40% strain may be in the range of about 300KPa to about 700 KPa, about 325 KPa to about 600 KPa, about 350 KPa toabout 500 KPa, or about 375 KPA to about 425 KPa. When unloading thematerial to an engineering strain of about 30%, the material exhibits anengineering stress of about 300 KPa, but in other examples, theengineering stress when unloading the material to about 30% strain maybe in the range of about 250 KPa to about 500 KPa, about 275 KPa toabout 450 KPa, about 300 KPa to about 400 KPa, or about 325 KPA to about375 KPa. When unloading to an engineering strain of about 20%, thematerial may have an engineering stress of about 100 KPa, but in otherexamples, the unloading engineering stress at about 20% may be in therange of about 50 KPa to about 200 KPa, about 75 KPa to about 150 KPa,or about 100 KPa to about 125 KPa. In some examples, the material may beconfigured to at least achieve a specific range or level of engineeringstress at each of the specified engineering strain levels describedabove, but in other examples, the material may be configured for lowerlevels of maximum engineering strain, e.g. up to about 30% or about 40%.

In some examples, certain portions of the stress/strain curve may have aparticular morphology. For example, for a particular level of maximumstrain the loading curve may be generally linear on the correspondingtrue stress/strain curve. In an example using a dressing describedherein, up to a true strain of about 45%, the loading curve had agenerally linear configuration. In other examples, the configuration mayonly be linear along a portion of the loading curve or may be curvedalong the entire loading curve. Where the loading curve is non-linear,the loading curve may be convex, concave or both. Also, in someexamples, the tangent line of the loading curve (i.e. the line betweenthe two triangles) may also be generally co-linear.

In some variations, the elastic material comprises a material having anelastic modulus E of at least about 1 MPa, about 1.5 MPa, about 2 MPa,about 2.5 MPa, about 3 MPa, about 3.5 MPa, about 4 MPa, about 5 MPa,about 6 MPa, about 7 MPa, about 8 MPa, about 9 MPa or at least about 10MPa or greater. The material elastic modulus E may be no greater thanabout 10 MPa, about 9 MPa, about 8 MPA, about 7 MPa, about 6 MPa, orabout 5 MPa, or about 4 MPa.

In addition to the absolute stress levels at certain strain levelsdescribed above, the material may also be characterized with respect tothe ratio between a) the stress to achieve a particular strain duringloading, and b) the stress at the same strain during unloading. Forexample, the material may have a ratio of at least 4:1 to about 3:2 ateach of the 20%, 30% and 40% strain levels, but in other examples, thematerial may exhibit these ratios only at 20%, at 30%, or at 40% strainlevels, or at both 20% and 30% but not 40%, or at both 30% and 40% butnot 20%. In other examples, the ratio at one, some or all of the strainlevels may be in the range of about 3:1 to about 2:1, or about 5:2 toabout 2:1.

In some examples, the elastic material of the dressing may be configuredunder testing conditions to achieve a stable level of stress at aconstant strain, e.g. the material exhibits a limited. amount of stressrelaxation over a particular period of time and at a particular level ofstrain. The period of time may be at least about 8 hours, about 12hours, about 18 hours, about 24 hours, about 36 hours, about 48 hours,about 72 hours, about 4 days, about 5 days, about 6 days, or about aweek or more. The level of strain may be about 10%, about 20%, about30%, about 40%, about 50%, about 60%, about 70%, or about 80% or more.The stress of the exemplary dressing over various time curves may beconfigured to maintain an engineering stress of about 300 KPa at anengineering strain of about 30% without noticeable deviation over aperiod of about 1 hour, about 2 hours, about 3 hours, about 4 hours,about 5 hours, about 6 hours, about 7 hours, or about 8 hours or more.The stresses at 10% strain, 20% strain, and at 40% may be lower orhigher.

In some variations, the elastic material or the dressing may beconfigured under testing conditions to maintain a particular minimumlevel of stress when held at a constant strain over a particular timeperiod. In an example to assess the ability of a backing material tomaintain a stress and strain on skin over time, engineering strains weremeasured while each backing material was tensile strained to 60% at arate of 100 microns per second and held for 10 minutes, and then droppedto a strain of 30% at a rate of 100 microns per second and held for 9hours. For example, the exemplary dressing is able to maintain anengineering stress level of about 350 KPa at an engineering strain of30%. In some other examples, the minimum level of stress may be about100 KPa, about 120 KPa, about 140 KPa, about 160 KPa, about 180 KPa,about 200 KPa, about 220 KPa, about 240 KPa, about 260 KPa, about 280KPa, about 300 KPa, about 320 KPa, about 340 KPa, about 360 KPa, about380 KPa, about 400 KPa, about 420 KPa, about 440 KPa, about 460 KPa,about 480 KPa, about 500 KPa, about 600 KPa, about 700 KPa, about 800KPa, about 900 KPa or about 1000 KPa or greater. The level of constantstrain may be different in other configuration, with a level of about15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%,about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, orabout 80%. The time period over which the dressing is able to maintain astress level may be at least about 2000 seconds, about 3000 seconds,about 4000 seconds, about 5000 seconds, about 6000 seconds, about 7000seconds, about 8000 seconds, about 9000 seconds, about 10000 seconds,about 20000 seconds, about 30000 seconds, about 40000 seconds, about50000 seconds, about 60000 seconds, about 70000 seconds, about 24 hours,about 36 hours, about 48 hours, about 72 hours, about 4 days, about 5days, about 6 days, about 7 days, about 10 days, about 2 weeks, about 1month or more. In some variations, the dressing, the elastic materialand/or the adhesive material is configured to exhibit less than about a15% change in stress or strain level over the particular period whenapplied to a skin surface or test surface. In other examples, the degreeof change may be about 12%, about 10%, about 8%, about 6%, about 5%,about 4%, about 3%, or about 2% or less. The stress or strain may be anengineering stress or strain, and/or a true stress or strain.

The adhesive used may be, for example, a pressure activated adhesive(PSA), as a silicone, acrylic, styrene block copolymer, vinyl ether,nitrile or other PSA. In other variations, a non-pressure sensitiveadhesive may be used, including but not limited a heat or light-curedadhesive. The pressure sensitive adhesive may be made from, e.g.,polyacrylate-based, polyisobutylene-based, silicone-based pressuresensitive adhesives, synthetic rubber, acrylic, and polyisobutylene(PIB), hydrocolloid, and the like. The T-peel release force and bluntprobe tack force of the adhesive may be measured by a standardized testmethod, such as ASTM D1876 and ASTMD2979 or other appropriate method. Insome variations, the T-peel release force or blunt probe tack test valueof the adhesive is configured to maintain loads of at least about 50mPa/mm for at least about 24 hours, about 48 hours, about 72 hours,about 1 week, about 2 weeks, about 3 weeks, about 4 weeks or more. Inother variations, the loads may be at least about 75 mPa/mm, about 100mPa/mm, about 125 mPa/mm, or at least about 150 mPa/mm over theparticular time period. The degree of adhesion e.g., as measured by theT-peel release force or blunt probe tack test value) may vary dependingupon the degree of strain placed onto the skin or incision site, and insome variations, these time periods may be based upon an average skinstrain of about 10%, about 20%, about 30%, about 40%, or about 50% ormore. In some variations, the adhesive may have a T-peel release forceof at least about 150 kg/m, about 160 kg/m, about 170 kg/m , about 180kg/m, about 190 kg/m, about 200 kg/m, about 210 kg/m, about 220 kg/m,about 230 kg/m, about 240 kg/m, about 250 kg/m, about 260 kg/m, about270 kg/m, about 280 kg/m, about 290 kg/m, about 300 kg/m, about 310kg/m, about 320 kg/m, about 330 kg/m, about 340 kg/m, about 350 kg/m,about 400 kg/m, about 450 kg/m, or at least about 500 kg/m or higher. Insome further variations, the T-peel release force may be no greater thanabout 1000 kg/m, about 900 kg/m, about 800 kg/m, about 700 kg/m, about600 kg/m, about 500 kg/m, about 400 kg/m or about 300 kg/m. The bluntprobe tack test value of the adhesive may be at least about 0.50 kg,about 0.55 kg, about 0.60 kg, about 0.65 kg, about 0.70 kg or about 0.75kg or higher, and may be no greater than about 1 kg, about 0.9 kg, about0.8 kg, about 0.7 kg, or about 0.6 kg. The T-peel release force andblunt probe tack force may be measured by a standardized test method,such as ASTM D1876 and ASTMD2979 or other appropriate method. Otherfeatures or variations of the device are described in U.S. applicationSer. No. 11/888,978, filed on Aug. 3, 2007, incorporated in its entiretyherein by reference.

The release liners may comprise any of a variety of materials, includingboth opaque and transparent materials. The release liners may compriseMylar or paper, or any other material with reduced adhesion to theadhesive material(s) of the device. For example, for a siliconeadhesive, a fluoropolymer-treated polyester film may be used, and for anacrylic pressure sensitive adhesive, a silicone treated polyester orMylar film or silicone treated craft paper may be used, in variationswhere the device has multiple separate adhesive regions, separaterelease liners may be provided for each region, or some regions may becovered by the same release liner.

Examples of dressings, applicators or tensioning devices that may beused in the devices kits or methods herein may include those provided inU.S. application Ser. No. 12/854,859 filed Aug. 11, 2010 and U.S.application Ser. No. 13/345,524 filed Jan. 6, 2012, and the disclosuresof which have been previously incorporated by reference in theirentirety without limitation.

Attachment structures of a dressing assembly, dressing carrier, support,base, applicator, tensioning or straining device may include anystructures that are used to attach or couple an applicator, tension orstraining device to a dressing. A dressing may or may not haveattachment features or structures. Any such attachment features may beintegral with or include any of the attachment structures orcorresponding structures to the attachment structures of the applicatordressing and/or tensioning device.

In some variations the assembly may comprise one or more mechanisms orelements configured to facilitate separation, release, removal ordetachment of the dressing from the applicator or tensioning device,other attachment elements or other portions of the dressing assembly,including but not limited to the separation devices and methodsdescribed in co-pending U.S. application Ser. No. 13/345,524 filed Jan.6, 2012. Release elements or releasable attachment structures mayinclude but are not limited to pockets and tabs, hook and loopmechanism, hooks, angled bars, pivoting, rolling, rocking or slidingfeatures associated with or coupled to attachment structures, adhesives,removable adhesives, adhesive tapes or other adhesive devices, pegs, ripcords, towel bar configurations, sliding pins, friction locks, camlocks, vacuum or suction devices, snap connectors, carpet tack, pressfit connections or other connections, levers, latches, locking members,spring members, for example, or other mechanisms such as cutters or ripcords or other structures or features to facilitate tearing, cutting orseparation of attachment structures or elements perforated or otherwiseseverable structures, that permit removal of dressing from theapplicator, other portions of the dressing assembly and/or attachmentstructures, features, elements or portions They may be self-releasinglatches or spring members. They may be actuated when a pressure memberis applied to a skin treatment device prior to removing the applicator,They may be manually actuated.

In some examples, the straining device may be configured to impartand/or maintain a single predetermined or pre-set strain or a pluralityof predetermined or pre-set strains, or predetermined maximum or minimumamounts of strain. A applicator, tensioning or straining device that isdescribed as being in an unstrained configuration is in a configurationin which a dressing may be unstrained or relatively less strained whenattached to the applicator, tensioning or straining device. Anapplicator, tensioning, or straining device that is described herein asbeing in a strained configuration, is in a configuration in which adressing may be strained or relatively more strained when attached tothe applicator, tensioning or straining device, or with respect to anunstrained configuration, when applied to a subject's skin.

Devices, applicators, tensioning devices, and corresponding attachmentfeatures may be configured to provide multi-direction strain oradditional strain in an orthogonal direction to a dressing. In somevariations, the attachment features may be configured to provide radialstrain (e.g., where the direction of the strain radiates from a centralregion of a dressing). For example, an applicator or tensioning devicemay radially strain the dressing such that the dressing applies aradially inward compressive force when adhered to the skin. Such devicesmay be typically circular, oval, egg, kidney bean, or other arcuateshapes disclosed elsewhere herein.

The applicator, tensioning device and/or attachment structure profilemay be straight, curved or otherwise varied. For example, the shape ofthe elements of a device may be configured to follow the shape of thearea of the subject's body to which the skin treatment device is to beattached. A tensioning device, applicator or elements thereof may beselected or configured to have a profile that has a desirable profilefor a particular body location or profile where the skin treatmentdevice is to be placed on a subject's skin. A applicator, tensioningdevice or elements thereof may be selected or configured to closelymatch a portion of a subject's body profile. The applicator ortensioning device and/or an element or segment thereof, may be curved,curvable, flexible, bendable, malleable, deformable, shapeable ormovable to provide alternative shapes or profiles of an attacheddressing. They may be relatively curved, curvable, flexible, malleable,bendable, deformable, shapeable or movable in at least one directionwhile being more rigid in another direction.

A variety of locking, latching, securing, attaching or detail mechanismsmay be used to maintain the applicator or tensioning device in a variousconfigurations including but not limited to unstrained, partiallystrained, strained configurations. A variety of locking, latching ordetent mechanisms may be used to maintain a dressing in a variety ofconfigurations including unstrained, partially strained, strained. Bylocking the, applicator, tensioning device, or dressing in a strainedposition, a predetermined strain of a given dressing may be achieved.The predetermined amount of strain may be a predetermined absolutepercentage of strain or level of force that is independent of the shapeand/or size of the treatment site. As a further example, this absolutepercentage of strain or level of force may or may not be independent ofthe minimum strain or force to achieve sutureless wound closure (e.g. arelative strain or three to achieve opposition of the incision edges ofa treatment site). Furthermore, the force needed to achieve woundclosure is not a predetermined strain or force, since the final level ofstrain or force is not known until opposition of the incision edges isachieved.

According to sonic variations, the cover and/or base or elements orsegments of a tensioning device may be constructed to be sufficientlyfirm or rigid or less flexible relative to an attached dressing tosupport an attached dressing until it is applied to a subject asdescribed with respect to the variations herein. Such material maycomprise, for example, a plastic, e.g., polypropylene, polycarbonate,polytetrafluoroethylene (PTFE or TEFLON®), LDPE, high-densitypolyethylene (HDPE), ultra high-molecular weight polyethylene (UHMWPE),polyvinyl chloride (PVC) or acrylic, nylon or a paperboard. The elementsor segments may be a laminate of a material, such as a solid bleachsulfate paperboard with a layer of flexible material between layers ofpaperboard, for example, silicone, polyurethane, LDPE or a rubbermaterial. The material may also be a metal as for example, ductilealuminum or stainless steel. The metal may comprise a foil, ribbon, wireor other form.

FIGS. 1A and 1B depict one variation of a wound treatment device 2,comprising an elastic layer of material 4 with an upper surface 6, alower surface 8, and edges 10, 12, 14 and 16. The lower surface 8 of theelastic layer of material 4 may comprise a central non-adhesive region18 flanked by two inner adhesive regions 20 and 22 along borders 24 and26. In this particular variation, the central non-adhesive region 18also has two borders 28 and 30 which are adhesive-free. Thisconfiguration may facilitate the treatment of longer incisional sites byserially placing the non-adhesive regions of multiple wound treatmentdevices along the incisional site, without the device edges directlyadhering to the incisional site.

In some variations, the average width of the non-adhesive region, i.e.the distance between the adhesive regions along the axis of strain (orwhere the device is strained along multiple dimension, the largestdimension of the device 2 along one of its axes of strain), is in therange of about 3 mm to about 15 mm or more, in some variations about 5mm to about 10 mm, and in other variations about 7 mm to about 8 mm. Thewidth of the adhesive region may be the same or greater than the widthof the non-adhesive regions, including but not limited to being 2×, 3×,or 4× or more in relative width. In some variations, the greater widthof the adhesive regions relative to the non-adhesive region may lowerfocal concentrations of tissue stress, which may reduce tissue strippingand/or blistering. The widths of the non-adhesive region and/or theadhesive regions may be constant or may be variable, and the widths ofthe adhesive regions may be the same or different.

The inner adhesive regions 20 and 22 may comprise outer borders 32 and34 which are opposite of the inner borders 24 and 26 shared with thecentral non-adhesive region 18 and shared with the outer non-adhesiveregions 36 and 38. The non-adhesive regions 36 and 38 may furthercomprise applicator attachment regions or structures 40 and 42 that areconfigured to releasably attach to an applicator that may be used toapply the device 2 to a treatment site. In some further variations, theattachment structures may also facilitate stretching of the centraladhesive region 18 and/or the adhesive regions 20 and 22. Variousexamples of applicators that may be used are described in greater detailbelow. In other variations, the applicator attachment structures 40 and42 may be located in adhesive regions that may or may not be contiguouswith more inner adhesive regions. In other variations, the elasticmaterial about the attachment structures may comprise an adhesive.Examples of applicators are described in greater detail below.

The applicator attachment structures 40 and 42 may comprise a pluralityof openings 44 and 46 located through the layer of elastic material 4.The openings 44 and 46 may be through-openings between the upper andlower surfaces. In other variations, the openings may be close-endedopenings, e.g. a plurality of pockets or even a single pocket spanningthe width or a portion of the width of the device.

In the variation depicted in FIGS. 1A and 1B, the openings 44 and 46 areconfigured to be fully penetrated by the applicator, but in othervariations, the applicator and/or the openings may be configured foronly partial insertion by the applicator. The openings 44 and 46 may becircular, ovoid, triangular, rectangular, square, polygonal or any otherof a variety of shapes. Each of the openings may have the same or adifferent shape, size or configuration, and the shape, size orconfiguration may vary between the upper surface and the lower surface.The openings may be also be angled with respect to the upper surface orlower surface, and in some variations, one or more openings and/or aregion about the openings may be partially or completely reinforced bywires, rings and/or frames and the like. In some variations, theapplicator attachment structures may also comprise denser or thickerregions of the elastic material. In some variations, multiple sets ofapplicator attachment structures may be provided to permit use ofdifferent applicators or to strain the device to different degrees, forexample.

FIGS. 6A to 6C depict another variation of the dressing 600 comprisingpockets 602 and 604 with inwardly facing pocket openings 606 and 608configured to receive the attachment structures of a correspondingapplicator. The pockets may comprise separate sheets of material thatare attached to the elastic material and may comprise the same or adifferent material as the other portions of the dressing. The separatesheets of material may be adhered to the elastic material usingadhesives, heat or plasma bonding, chemical bonding or mechanicalattachment structures (e.g. staples and stitches). In the exampledepicted best in FIGS. 6B and 6C, the pockets 602 and 604 may beintegrally formed structures of the base layer 610 that are folded overfrom the ends 612 and 614 of the dressing 600 and attached onto itselfalong the edges 616 and 618 without bonding the opening edge 620 to formthe opening 606. In other variations, such as the dressing 630 depictedin FIG. 7A, the inner portions 632 of a pocket structure 634 or thedistal edge 636 may also be adhered or fused to form multiple subpockets638 and 640. Although FIG. 43A depicts a dressing with two subpockets638 and 640, in other variations, three, four, five, six, seven, eightor more subpockets may be provided. The area or width of the fused innerportion(s) 652 may also vary, as shown in the dressing 650 in FIG. 7B.The width of the fused inner portion(s) may be in the range of about 0.5mm to about 10 mm or more, sometimes about 1 mm to about 5 mm, and othertimes about 1 mm to about 2 mm. As shown in the dressing 660 of FIG. 7C,in other variations, the subpockets 662 and 664 may also be separatelyprovided without an inner portion interconnecting them. In some furthervariations, the opening(s) of the pocket structures may be closed orsealed shut after application. Closure may result from using anadhesive, complementary sealable groove structures about the pocketopenings (e.g. sandwich bag seal) or as a result of the cohesiveproperties of the elastic material when the pocket is pressed down.Closure of the pockets may reduce the risk of snagging the dressingfollowing its application.

In other variations, the applicator attachment structures may compriseone or more projections or other structures protruding from the surfaceof the wound treatment device that form a mechanical or frictionalinterfit with the applicator. Referring to FIGS. 8A to 9B, examples ofthese alternate attachment structures include T-bar 672 or eyeletprojections 682 of the dressings 670 and 680 that may be releasablyengaged by an applicator. The t-bar 672 and eyelet projections 682, maybe integrally formed with the base elastic layer 674 and 684 of thedressings 670 and 680, or may comprise a different material that ispartially embedded in the elastic layer 674 and 684. In still othervariations, the t-bar or eyelet projections may comprise individual orcommon base or pad structures that may be adhered to the surface of theelastic layer 674 and 684. The number of projecting attachmentstructures per side of the dressing may be in the range of about one toabout twelve or more, sometimes about three to about eight, and othertimes about four to about five.

In still another variation, the dressing may comprise complementaryhook-and-loop attachment regions VELCRO(®) that may releasably attach toan applicator with a corresponding hook-and-loop attachment regions. InFIGS. 10A to 10C, for example, the bandage 700 comprises loop attachmentregions 702 and 704 that are adhered to the upper surface 706 of thebandage 700, and with various adhesive regions 708 a/b and 710 a/blocated on the lower surface 712. In use, a corresponding applicator,including but not limited to the exemplary applicator 714 depicted inFIG. 11, is squeezed or compressed to reduce the spacing betweencorresponding hook regions 716 and 718 to correspond to the spacing ofthe loop attachment regions 702 and 704 of the bandage 700 in itsunstretched state. The hook regions 716 and 718 are aligned and thenpressed against the loop attachment regions 702 and 704 to engage thebandage 700. In some examples, the applicator 714 may comprise a lockingmechanism 720 to maintain the applicator 714 in a compressed stateduring engagement of the bandage 700, but in other examples, such as theapplicator 730 in FIG. 12, the user will manually maintain theapplicator 730 in a compressed state to align its hook regions 732 and734 to the loop regions 702 and 704 to engage the bandage 700. A lockingmechanism is not used. In some alternate application procedures, theapplicator 714 (or 730) is not squeezed and instead, one of the loopregions 702 and 704 of the bandage 700 is first attached to acorresponding hook region 716 or 718, for example, and then the bandage700 may be stretched and the remaining loop region 702 or 704 isattached to the applicator 714.

Although the examples in FIGS. 10A to 12 illustrate the loop regions 702and 704 on the bandage 700 and the hook regions 716 and 718 located onthe applicator 714, for example, in other variations, the relativerelationships between the hook and the loop attachment regions may bereversed. The hook-and-loop attachment regions may be provided on any ofthe variety of dressing applicators the variety of applicators describedherein.

In some variations, one or more flap regions 49 and 51 may be providedadjacent to the outer non-adhesive regions 36 and 38, or the applicatorattachment structures 40 and 42. Each of the flap regions 49 and 51 maybe located directly between an edge 10 and 12 of the treatment device 2and the outer non-adhesive regions 36 and 38 or applicator attachmentstructures 40 and 42. During use or preparation of the treatment device2 for application to the skin, the flap regions 49 and 51 may remainunstretched relative to the central non-adhesive region 18 and inneradhesive regions 20 and 22. Once the adhesive regions 20 and 22 areadhered to the skin, the flap regions 49 and 51, which may optionallyalso comprise an adhesive on their skin contacting surface, may beadhered to the skin. The flap regions may be adhered to the skin in anunstrained state, or in a strained state that is less than, equal to, orgreater than the strain in the central non-adhesive region 18 andadhesive regions 20 and 22. In still other variations, the flap regionsmay be cut or separated from the dressing after the dressing is applied.Perforations may be provided between the adhesive regions and the flapregions to facilitate separation.

The adhesive provided on the lower surface of the flap regions 49 and 51may be the same or may be different than the adhesive of the inneradhesive regions 20 and 22, including but not limited to thecomposition, thickness and/or distribution of the adhesive material. Insome variations, the adhesive of the flap regions 49 and 51 may have areduced T-peel release force and/or blunt probe tack force relative tothe adhesive provided for the inner regions 20 and 22. Various T-peelrelease force and/or blunt probe tack force ranges for the adhesive areprovided below. In some variations, the unstrained or less-strained flapregions may redistribute at least some of the strains acting on tissueabout the transition regions along the outer borders 32 and 34 of theinner adhesive regions 20 and 22. This may or may not reduce the risk ofskin stripping or blistering compared to devices without flap regions orwith flap regions of smaller width. In some variations, the actual widthof a section of the flap region or the average width of the flap regionor (or adhesive portion of the flap region) may be characterizedrelative to the corresponding width of the closest inner adhesive regionand/or the width of the closest outer non-adhesive region. The width ofthe flap region may be in the range of about 1 mm to about 10 cm ormore, sometimes about 5 mm to about 3 cm, and other times about 1 cm toabout 2 cm. The size of the flap region may be also characterizedrelative to the size of the other regions of the dressing. For example,in some variations, the width of the flap region may be at least about25%, about 33%, about 50%, about 75%, about 100%, or about 120% orhigher than the corresponding width of the closest inner adhesiveregion. The width of the flap region relative to the closest outernon-adhesive region may be at least about 50%, about 75%, about 100%,about 120% or higher.

The stretching of the adhesive regions when applied to the skin surfacemay result in an increased tissue density under the adhesive region.This may be the result of generally planar, tangential or parallelcompression of skin tissue that is directly attached to that adhesiveregion, resulting from the relaxation of the adhesive region. In someexamples, this tissue compression may reduce the risk of tissuestripping and/or blistering of skin in direct contact with the adhesive,in contrast to bandage “strapping” where one end of a bandage is adheredto the skin and then tensioned or pulled across a wound before the otherend is attached to the skin on the opposite side of the wound.

Furthermore, bandage “strapping”, while generating tension in thebandage during the application, may simultaneously generate a relativelyhigh tissue strain at the first adhesion site. This high tissue strainthen decreases when the bandage is attached to the skin at a secondadhesion site as the high peak stresses are redistributed along the skinunder the bandage. In contrast, when a pre-strained bandage is appliedto the skin, little if any strain may be transferred or generated in theskin as the adhesive regions are applied to the desired locations. Whenthe pre-strained bandage is permitted to relax, however, the strain (orpeak strain) in the skin may be increased. Thus, with a pre-strainedbandage, temporary high tissue strain may be avoided or otherwisereduced during the application procedure. In other variations, however,the device 2 may also be applied to the skin by strapping, or by acombination of pre-straining and strapping.

Although the depicted wound treatment device 2 may have a generallyrectangular configuration with a size of about 80 mm to about 40 mm, inother variations the device may have any of a variety of lengths andwidths, and may comprise any of a variety of other shapes. Also, thecorners of the device may be squared or rounded, for example. Thelengths and/or widths of the device may be in the range of about 5 mm toabout 1 meter or more, in some variations about 20 mm to about 500 mm,and in other variations about 30 mm to about 50 mm, and in still othervariations about 50 mm to about 100 mm. In some variations, the ratio ofthe maximum dimension of the wound device (e.g. its length) to anorthogonal dimension to the maximum dimension (e.g., width), excludingthe minimum dimension of the device (e.g. the thickness), may be in therange of about 1:1, about 2;1, about 3:1, about 4:1 about 5:1, about6:1, about 7:1, about 8:1, about 9:1 or about 10:1 or greater. In somevariations, the strain axis of the device in use may be oriented withrespect to the maximum dimension or to the orthogonal dimension to themaximum dimension.

The elastic material of the device may comprise a single layer ofmaterial or multiple layers of the same or different materials. Thematerial may have any of a variety of configurations, including a solid,foam, lattice, or woven configuration. The elastic material may be abiocompatible polymer, e.g., silicone. The thickness of polymer sheets,e.g., silicone polymer sheets or shape memory polymer sheets, may beselected to provide the devices or bandages with sufficient loadcarrying capacity to achieve desired recoverable strains, and to preventundesired amounts of creep deformation of the bandages or devices overtime. In some variations, the thickness across devices or bandages isnot uniform, e.g., the thickness across the device may be varied tochange the stiffness, the load carrying capacity, or recovery strains inselected orientations and/or locations. The elastic material may have athickness in the range of about 50 microns to 1 mm or more, about 100microns to about 500 microns, about 120 microns to about 300 microns, orin some variations about 200 microns to about 260 microns. In someexamples, devices having an edge thickness of about 500 microns or less,400 microns or less, or about 300 microns or less may exhibit less riskof skin separation from inadvertent lifting when inadvertently brushedagainst clothing or objects. In some variations, the devices or bandagesare tapered near the edges to reduce thickness. A tapered edge may alsoameliorate peak tensile forces acting on skin tissue adjacent to theadhesive edges of the wound treatment device. This may or may not reducethe risk of skin blistering or other tension-related skin trauma. Inother variations, the edges of the devices or bandage may be thickerthan the middle of the device or bandage. It is hypothesized that insome configurations, a thicker device or bandage edge may provide arelative inward shift of the location of the peak tensile forces actingnear the device or bandage edge, compared to devices or bandages ofuniform thickness.

The adhesive regions may comprise a pressure sensitive adhesive, e.g.,polyacrylate-based, polyisobutylene-based, silicone-based pressuresensitive adhesives, and the like, The T-peel release force and bluntprobe tack force of the adhesive may be measured by a standardized testmethod, such as ASTM D1876 and ASTMD2979 or other appropriate method. Insome variations, the T-peel release force or blunt probe tack test valueof the adhesive is configured to maintain loads of at least about 50mPa/mm for at least about 24 hours, about 48 hours, about 72 hours,about 1 week, about 2 weeks, about 3 weeks, about 4 weeks or more. Inother variations, the loads may be at least about 75 mPa/mm, about 100mPa/mm, about 125 mPa/mm, or at least about 150 mPa/mm over theparticular time period. The degree of adhesion (e.g. as measured by theT-peel release force or blunt probe tack test value) may vary dependingupon the degree of strain placed onto the skin or incision site, and insome variations, these time periods may be based upon an average skinstrain of about 10%, about 20%, about 30%, about 40%, or about 50% ormore. In some variations, the adhesive may have a T-peel release forceof at least about 150 kg/m, about 160 kg/m, about 170 kg/m , about 180kg/m, about 190 kg/m, about 200 kg/m, about 210 kg/m, about 220 kg/m,about 230 kg/m, about 240 kg/m, about 250 kg/m, about 260 kg/m, about270 kg/m, about 280 kg/m, about 290 kg/m, about 300 kg/m, about 310kg/m, about 320 kg/m, about 330 kg/m, about 340 kg/m, about 350 kg/m,about 400 kg/m, about 450 kg/m, or at least about 500 kg/m or higher. Insome further variations, the T-peel release force may be no greater thanabout 1000 kg/m, about 900 kg/m, about 800 kg/m, about 700 kg/m, about600 kg/m, about 500 kg/m, about 400 kg/m or about 300 kg/m. The bluntprobe tack test value of the adhesive may be at least about 0.50 kg,about 0.55 kg, about 0.60 kg, about 0.65 kg, about 0.70 kg or about 0,75kg or higher, and may be no greater than about 1 kg, about 0.9 kg, about0.8 kg, about 0.7 kg, or about 0.6 kg. The T-peel release force andblunt probe tack force may be measured by a standardized test method,such as ASTM D1876 and ASTMD2979 or other appropriate method. Otherfeatures or variations of the device are described in U.S. applicationSer. No. 11/888,978, filed on Aug. 3, 2007, which was previouslyincorporated by reference. In some variations, the final compressivestress and strain imposed onto the skin by the elastic material 4 may bethe result of the dynamic equilibrium between the tensile stress in theskin and the elastic material 4 of the wound treatment device 2.

The wound treatment device 2 may be configured to impose a skin strainin the range of about 10% to about 60% or more, in other configurationsabout 15% to about 50%, and in still other configurations, about 20% toabout 30% or about 40%. To achieve the desired degree of skin strain,the wound treatment device 2 may be configured to undergo elastictensile strain in the range of about 20% to about 80% or more, sometimesabout 30% to about 60%, and other times about 40% to about 50% or about60%. The device 2 may comprise any of a variety of elastic materials,including but not limited to silicones, styrenic block copolymers,natural rubbers, fluoroelastomers, perfluoroelastomers, polyether blockamides, thermoplastic elastomers, thermoplastic polyurethane,polyisoprene, polybutadiene, and the like. The material may have a ShoreA durometer in the range of about 20 to about 90, about 30 to about 80,about 50 to about 80, One example of the elastic material 4 is MED82-5010-05 by NUSIL TECHNOLOGY LLC (Carpinteria, Calif.). Other examplesof suitable materials are described in U.S. application Ser. No.11/888,978, which was previously incorporated by reference in itsentirety.

When the strained device 2 is applied to a skin location and allowed toat least partially recover to its base configuration, the recovery levelor equilibrium level of strain in the device may be in the range ofabout 10% to about 60% or more, in other configurations about 15% toabout 50%, and in still other configurations, about 20% to about 30% orabout 40%. The ratio between the initial engineering tensile strainplaced onto the device 2 before recovery and the resulting engineeringcompressive strain in the skin may vary depending upon the skin type andlocation, but in some examples, may be about 2:1. In other examples, theratio may be in the range of about 4:1 to about 5:4, about 3:1 to about5:3, or about 5:2 to about 2:1. These skin strain characteristics may bedetermined with respect to a reference position of the body or bodypart, e.g. anatomical position, to facilitate reproducible measurements.The particular degree of strain may be characterized as either anengineering strain or a true strain, but may or may not be calculatedbased upon or converted from the other type of strain (e.g. the strainmay be based upon a 60% engineering strain that is converted to a truestrain).

Referring to FIGS. 2A and 2B, the wound treatment device 2 may beprovided with one or more release liners 52, 54 and 56 to protect one ormore of the adhesive regions 20, 22, 48 and 50, The release liners 52,54 and 56 may be configured with one or more flaps or tabs 58, 60, 62,64, 66 and 68 that project from the edges 10, 12 or surfaces 6, 8 of thetreatment device 2 to facilitate grasping or removal of the releaseliners 52, 54 and 56. FIG. 2C depicts the liners 52, 54 and 56 withoutthe wound treatment device 2. In some examples, the release liners mayresist inadvertent adhesion of the wound treatment device to itself orother surfaces during loading of the device onto an applicator, orduring application of the device to the skin. In variations where thedevice has multiple separate adhesive regions, separate release linersmay be provided for each region, or some regions may be covered by thesame release liner. Referring back to FIG. 2A and 2B, the three releaseliners 52, 54 and 56 are provided to cover the four adhesive regions 20,22, 48 and 50, with two end release liners 52 and 54 covering the flapregions 49 and 51, respectively and a single release liner 56 coveringboth inner adhesive regions 20, 22. The end release liners 52 and 54each comprise two tabs 58 and 60 which project from the same edge 10 and12, respectively, of the device, but in other variations, one or moretabs may project from the other edges 14 and/or 16, from multiple edges,or from no edges. The central release liner 56, for example, comprisestabs 66 and 68 that project from opposing edges 10 and 12 of the device.Although the tabs 58, 60, 62 and 64 are depicted as aligned with theedges 14 and 15 of the treatment device 2, in other variations theliners may be configured with tabs at other locations, or with adifferent number of tabs. In some variations, the tabs may also befolded or creased, which may facilitate grasping where the tabs arelocated against a surface rather than projecting from an edge.

In variations comprising multiple release liners, the liners may or maynot be removed at different times or in a particular order. In somevariations the liners may include indicia to facilitate removal in aparticular order. The indicia may comprise alpha-numeric characters 70and 72, color, graphic symbols and the like, and may be located on thebody of the liner or on the tabs, if any. In FIGS. 2A and 2B, forexample, users may be instructed to remove the central liner 56 duringthe loading of the treatment device 2 onto an applicator and/or forapplication to a skin site. After the initial adherence of the treatmentdevice 2 to the skin, the outer release liners 52 and 54 covering theflap regions 49 and 51 may then be removed to permit adherence of therest of the treatment device 2.

The release liners may comprise any of a variety of materials, includingboth opaque and transparent materials. The release liners may compriseMylar or paper, or any other material with reduced adhesion to theadhesive material(s) of the device. In some examples, the central liner56 (or a different liner) may be reapplied to the inner adhesive regions20 and 22 after the treatment device 2 is loaded onto an applicator,which may protect the adhesive materials until actual application to theskin. The liners may comprise different surface geometries, e.g. surfaceroughness, and/or indicia that may permit identification of the originalliner surface that was applied to the adhesive regions, which may reducedegradation of the adhesive regions from dust, dander and/or othersubstances if the incorrect side of the liner is reapplied to thedevice.

As noted previously, an applicator, tensioning device and/or strainingdevice may be provided in some embodiments to impart a strain to a skintreatment device with an external force and/or to maintain a strainimparted to the skin treatment device. In some examples, the strainingdevice may be configured to impart and/or maintain a singlepredetermined or pre-set strain or a plurality of predetermined orpre-set strains. Features described herein with respect to an applicatormay also be used in any tensioning or straining device that is used tostrain a skin treatment device. An applicator, tensioning or strainingdevice that is described as being in an unstrained configuration is in aconfiguration in which a skin treatment device may be unstrained orrelatively less strained when attached to the applicator, tensioning orstraining device. An applicator, tensioning, or straining device that isdescribed herein has being in a strained configuration is in aconfiguration in which a skin treatment device may be strained orrelatively more strained when attached to the applicator, tensioning orstraining device. Features described herein with respect to anapplicator may also be used in any tensioning or straining device thatis used to strain a skin treatment device.

A skin treatment device that is described herein is a device that may beapplied, attached to or coupled to one or more layers of the skin of asubject and may include without be limited to, a wound treatment device,a dressing, bandage, or other device.

Attachment structures of an applicator, tensioning or straining devicemay include any structures that are used to attach or couple anapplicator, tension or straining device to a skin treatment device. Suchdevices may include but are not limited to pockets and tabs, hook andloop mechanism, hooks, angled bars, adhesives, removable adhesives,pegs, rip cords, towel bar configurations, sliding pins , frictionlocks, cam locks, vacuum or suction devices, snap connectors, carpettack, press fit connections or other connections.

The attachment structure profile may be straight, curved or otherwisevaried. For example, the shape of the attachment structures may beconfigured to follow the shape of the area of the subject's body towhich the skin treatment device is to be attached. A tensioning deviceor applicator may be selected or configured to have a profile that has adesirable profile for a particular body location or profile where theskin treatment device is to be placed on a subject's skin. A tensioningdevice or applicator may be selected or configured to closely match aportion of a subject's body profile. The attachment structures may becurved, curvable, bendable, deformable, shapeable or movable to providealternative shapes or profiles of an attached skin treatment device.

Attachment features or structures of a skin treatment device may includeany of the attachment structures or corresponding structures to theattachment structures.

Attachment structures and corresponding attachment features may beconfigured to provide multi direction strain or additional strain in anorthogonal direction.

In some variations the applicator may comprise a mechanism configured tofacilitate separation, release, removal or detachment of the attachmentstructures of the applicator from the attachment features of the skintreatment device, including but not limited to the separation devicesand methods described herein. Releasing mechanisms may include but arenot limited to pivoting, rolling, rocking or sliding features associatedwith or coupled to attachment structures of the applicator. They may beself-releasing latches or spring members. They may be actuated when apressure member is applied to a skin treatment device prior to removingthe applicator. They may be manually actuated. The mechanisms mayinclude levers, latches, locking members, spring members, for example.

A variety of locking, latching or detent mechanisms may be used tomaintain the applicator in a various configurations including but notlimited to unstrained, partially strained, strained, unstamped, orstamped configurations. A variety of locking, latching or detentmechanisms may be used to maintain a skin treatment device in a varietyof configurations including unstrained, partially strained, strained. Bylocking an applicator in a strained position a predetermined strain of agiven skin treatment device may be achieved. Other locking mechanisms,including but not limited to other locking mechanisms described hereinmay be used. A variable locking mechanism may be used to vary the amountof strain for a given skin treatment device. Such mechanisms may bereleasable to permit straining, stamping, release of the attachmentstructures from the skin treatment device, or to release variousstructures to permit reloading of the device.

An actuator, actuation force may be used or applied at any point duringstraining of a skin treatment device and is externally applied to theapplicator, either manually or otherwise. Optionally, an actuator orhandle may be provided that provides a mechanical advantage greater than1 at least at some point when actuated. Optionally a mechanicaladvantage may increase as a device is strained.

Applicators configured with any of a variety of force transfermechanisms may be used to transfer forces exerted onto the applicator tothe skin treatment device, including but not limited to leaf springs,helical springs, pneumatic or hydraulic struts, sliders, helicallythreaded shafts, articulated linkages, pivoting levers, and the like.The force transfer mechanisms may be configured to transfer theresulting force onto the skin treatment device along the same directionas the originally exerted force, or in other configurations along adifferent direction.

Applicators described herein may provide accessible areas or spaces toaccess areas where the skin treatment device is applied to the skin sothat the adhesive may be pressed on to the skin. The adhesive used maybe, for example, a pressure activated adhesive (PSA), as a silicone,acrylic, styrene block copolymer, vinyl ether, nitrile or other PSA. Inother variations, a non-pressure sensitive adhesive may be used,including but not limited a heat or light-cured adhesive.

In some variations, the applicator may comprise an attachmentconfiguration that facilitates attachment of a device to the applicator,and a delivery configuration that stretches or strains the attacheddevice by about 20%, about 30%, about 40%, about 50%, about 60%, about70%, about 80%, about 90%, about 100%, or about 110% or more, relativeto its unstretched or unstrained configuration. The applicator may havea greater strain in the attachment configuration than in the deliveryconfiguration. The applicator may he configured such that the strain itimposes generally falls within with a one or two-sided tolerance ofabout 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%,about 9%, about 10%, about 15%, or about 20%, for example. The load perwidth imposed by the applicator onto the treatment device along its axisof tensile strain may vary, depending upon the amount of desired strainand the material characteristics of the device. For example, theapplicator may be configured to exert a engineering strain of about 60%to the device using a load per millimeter width that is in the range ofabout 0.1N to about 1N, about 0.2N to about 0.8N, about 0.3N to about0.6N, or sometimes in the range of about 0.4N to about 0.5N or 0.6N. Inanother example, the applicator may be configured to exert a strain ofabout 40% to the device using a load per millimeter width that is in therange of about 0.05N to about 0.6N, about 0.1N to about 0.5N, about 0.2Nto about 0.4N, or about 0.3N to about 0.4N. In still another example,the applicator may be configured to exert a strain of about 30% to thedevice using a load per millimeter width that is in the range of about0.05N to about 0.5N, about 0.1N to about 0.3N, or about 0.2N to about0.3N.

The applicator may also be characterized by the force required tocompressively strain the applicator to a particular strain level, and/orby the force the applicator exerts when the applicator is compressed toa particular strain level. For example, the applicator may be configuredto be compressively strained to about 40% using a load per millimeterwidth (or dimension transverse to the direction of strain) that may beat least about 0.1N, about 0.2N, about 0.3N, about 0.4N, about 0.5N,about 0.6N, about 0.7N, or about 0.8N or greater. In other examples, theapplicator may be configured to be compressively strain to about 20%using a load per millimeter width (or transverse dimension) that is atleast about 0.05N, about 0.1N, about 0.2N, about 0.3N, about 0.4N, about0.5N or greater. In some variations where the material exhibits littlehysteresis on it stress/strain curves, the loading force and theunloading force at a particular level of strain may be the same orsimilar.

FIGS. 3A to 4D depict one example of an applicator 100 that may be usedto generate the strain and/or maintain strain in the device forapplication to a treatment site. The applicator may comprise a resilientelastic or spring body comprising an expanded or relaxed configuration(as shown in FIGS. 3A to 3D) and a retracted or constrainedconfiguration (as shown in FIGS. 4A to 4D). The applicator 100 maycomprise an elastic body 102 with first and second device attachmentstructures 104 and 106 that are configured to releasably engage theapplicator attachment structure 40 and 42 of the treatment device 2illustrated in FIGS. 1A to 2B. Here, the attachment structures 104 and106 comprise a plurality of projections 108 and 110 that may be insertedinto the openings 44 and 46 of the devices. The projections may have anyof a variety of shapes, orientations, sizes or thicknesses. In thisparticular variation, the projections 108 and 110 are angled upwardsfrom the base structures 112 and 114 of the applicator 100 (e.g. awayfrom an attached device). The angle may be anywhere in the range ofabout 0 degrees to about 90 degrees or more, in some variations about 15degrees to about 75 degrees, and in other variations about 25 degrees toabout 45 degrees. The angles of the projections 108 and 110 may beuniform or non-uniform between the two sets or between individualprojections. The shape of the projections may be square, rectangular,triangular, bulbous, mushroom-like, or the like. In some variations, thetransverse dimension of the projections may be greater than thecorresponding transverse dimension of the openings 44 and 46 of thetreatment device 2, which may result in stretching or deformation of theopenings 44 and 46 when attached to the applicator 100. The resistancefrom the deformation of the openings 44 and 46 may reduce the rate ofinadvertent detachment of the treatment device 2 from the applicator100. In variations comprising a mushroom or bulbous configuration, therounded distal end of the projection may reduce the risk of damaging thedevice during loading, while the increased transverse dimension of theprojection distally and the reduced transverse dimension of theprojection proximally may provide tactile feedback to the user duringloading that may indicate proper loading, and may also reduce the riskof device damage by reducing stretching of the openings once loaded. Theprojections may have a length of about 500 microns to about 5 mm ormore, in some variations about 1 mm to about 4 mm, and in othervariations about 2 mm to about 3 mm. The thickness of the projectionsmay be the same, lower or greater than the elastic body 102 of theapplicator 100. The elastic body 102 may comprise any of a variety ofelastic materials, including but not limited to polymeric and metallicmaterials. In other variations, generally malleable polymeric ormetallic materials may be used.

To facilitate the application of pressure against the device 2 and ontothe skin, the base structures 112 and 114 may further comprise pressurepads 116 and 118 or other padded/deformable structures that may conformto the contours of the skin surface, which may redistribute forcesexerted onto the treatment device 2 through the applicator 100 acrossthe surfaces of the pads 116 and 118. The pressure pads 116 and 118 maycomprise any of a variety of deformable materials, including foams (openand closed cells), gels, and the like.

In some variations, the device may comprise further indicia that may beused to indicate proper loading and/or straining of the device. In FIGS.1A and 2A, for example, the geometry of lines 74 and 76 may be remaingenerally linear when all of the openings 40 and 42 of the treatmentdevice 2 are engaged by the projections 108 and 110, but may be deformedor become non-linear if one or more of the openings 40 and 42 aremissed, due to variations in the degree of stretching across thetreatment device 2. The lines 74 and 76 may also align withcorresponding indicia on the applicator 100 (e.g. the base structures112 and 114 and/or the pressure pads 116 and 118) to indicate properloading and/or stretching of the treatment device 2.

In some variations, the applicators may be manually maintained in aretracted state by the user during loading by squeezing or otherwiseexerting compressive forces onto the applicator. In other variations, asshown in FIGS. 3A to 4D, the applicator 100 may comprise a lockingmechanism 120 that may be used to maintain the applicator 100 in one ormore configurations. In this particular variation, the locking mechanism120 comprises a latch 122 that releasably engages a tab 124 located inan opening 126 or recess of the elastic body 102. The latch 122 may hebiased against the tab 124 such that as the tab 124 slides along thelength of the latch 122 as the elastic body 102 is compressed, until thetab 124 engages a tab opening 134 (depicted in FIGS. 4A, 4C and 4D) onthe latch 122 and locks in the compressed configuration of the elasticbody 102. To resist complete disengagement between the latch 122 and theopening 126 in the elastic body 102, the opening 126 may comprise aretention bar 128 that the distal section 130 of the latch 122 may bewrapped around. The latch 122 may be attached to the elastic body 102 bya rivet 132, or by welding or gluing, for example. In other examples,the latch may be integrally formed by laser cutting or punching out thelatch structure from the elastic body. In some variations, theapplicator may be configured with two or more latches.

In other variations, the latch may not be biased against the tab and maybe manually engaged the user at the desired locking position. In othervariations, the latch may have a plurality of tab openings to permitlocking into a variety of configurations. In still other variations, thelatch may comprise a projection or tab that engages an opening or recessof the elastic body. In alternate variations, the locking mechanism maycomprise a ratchet mechanism, locking pin mechanism, or resistancescrew, for example.

FIGS. 3A to 3D depict the applicator 100 in its base configuration withreduced strain, if any. To facilitate loading of the treatment device 2.the applicator 100 may be compressed, until the applicator 100 is lockedinto a compressed configuration, as illustrated in FIGS. 4A to 4D, whichmay reduce the degree of stretching, if any, needed to load the deviceonto the applicator 100, as depicted in FIGS. 5A and 5B. Once the deviceis loaded, the locking mechanism 120 may be disengaged by pressing thelatch 122 away from the locking tab 124. The potential energy in theelastic body 102 from its compression is then released to permitstretching of the attached treatment device 2 and is ready for adhesionto the skin. As shown, the elastic body 102 comprises a sheet ofsemi-rigid material, but in other variations, may have a frame-likeconfiguration. In some variations, the elastic body, may comprisestainless steel with a thickness in the range of about 500 microns toabout 3 mm or more, in some variations about 1 mm to about 2 mm, and inother variations about 1 min to about 1.5 mm. The elastic body 102 maybe configured with as a number of angled panel regions, as depicted inFIGS. 3A to 4D, with generally horizontal base structures 112 and 114that may be generally orthogonal to side panels 140 and 142, which inturn form an angle of about 135 degrees each (as measured from theinferior surface of the elastic body 102) with the central panels 144and 146 which in turn may be generally oriented at about a 90 degreeangle with each other. The angles between the panels may be sharp anglesor rounded angles, and may be configured differently depending upon theparticular skin site (e.g. limb vs. torso), or degree of desired strain(e.g. a more obtuse angle between the central panels 144 and 146). inother variations, the angle between any two panels or base structure maybe in the range of about 0 to about 360 degrees, in some variationsabout 45 to about 135 degrees, and in other variations about 75 to about90 degrees (as measured from the underside or topside of the elasticbody 102). The latch mechanism 120 may be attached or involve thecentral panels as shown in FIGS. 3A to 4D, but in other variations maybe attached or involve the side panels or base structures. In othervariations, the elastic body may comprise a curved structure, includingbut not limited to an omega-shaped structure. As illustrated in FIGS. 3Ato 5B, the non-planar configuration of the applicator 100 provides anopen region 150 between the pressure pads 116 and 118 and side panels140 and 142, which permits access to the superior surface of an attacheddevice to facilitate positioning of the device to a treatment siteand/or to permit direct access or the application of pressure to thecentral portion of a device by the user (e.g. using fingers or otherinstrument). As shown in FIGS. 5A and 5B, the treatment device 2 and theapplicator 100 may be configured so that the inner adhesive regions 20and 22 are generally located underneath the pressure pads 20 and 22 whenthe treatment device 2 is loaded onto the applicator 100.

Various applicators and/or tensioning devices may be used to pre-tensionand apply the wound devices 2300, 2310 for the application of uni-axial,bi-axial (or other multi-axial) compressive force to the treatment siteare described. For example, applicators and/or tensioning devicesdescribed in U.S. patent application Ser. No. 12/854.859 (including, forexample, the multi-axial device in FIG. 54A-54E) and U.S. Pat. No.7,683,234 (including, for example, the multi-axial devices in FIGS.8A-B, 9A-B) may be used to apply multi-axial compression wound devices.U.S. patent application Ser. No. 12/854,859 and U.S. Pat. No. 7,683,234are both hereby incorporated by reference in their entirety.

In some variations, the use of two opposing and collapsible walls toseparate to slidable walls of a fixed configuration, as illustrated inthe applicator depicted in FIGS. 13A to 131, for example, may provide amechanical advantage when applying a strain to a skin treatment device.A mechanical advantage may be characterized by an output force that isgreater than the input force, and may be described as a ratio of theoutput force divided by the input force that is greater than 1. In somevariations, the mechanical advantage may be at least about 1.1, about1.2, about 1.3, about 1.4, about 1.5 about 1.7, or about 2 or more. Themechanical advantage may or may not be provided throughout the entiremovement range of the applicator.

FIGS. 13A to 13D illustrate another variation of a tensioning device,straining device or an applicator 1200. The applicator 1200 comprises ahandle 1201 or actuator configured to be actuated to strain a skintreatment device 1240 and/or to apply the device to the skin of asubject. The applicator 1200 includes end attachment structures 1206,1207. In some variations, the applicator may also include sideattachment structures 1203, 1204, 1220, 1222 that may interface withstructures 1203 and 1204 be attached to the sides of a skin treatmentdevice. This interface may provide a second dimension or axis to thetension or strain applied to the skin treatment device. Thus the skintreatment device may be strained in orthogonal directions or at leasttwo directions, i.e., the applicator provides a bi-directionally ormulti-directionally strained skin treatment device. The attachmentstructures may be located on the bottom of bump features 1245 on wallsegments 1220, 1222. The attachment structures 1206, 1207 may compriseengagement flaps having edges that engage attachment features 1246, 1247of a corresponding skin treatment device 1240. Attachment structures1203, 1204 as shown are hook or loop structures that have correspondinghook or loop structure attachment features on the back side of the skintreatment device. The applicator or skin treatment device attachmentstructures may comprise other types of attachment structures, includingbut not limited to other attachment structures described or set forthherein.

The applicator 1200 may further comprise moveable, slidable or acollapsing or expanding bottom frame structure 1202, opposing fixedconfiguration walls 1208, 1209 and opposing movable, pivotable or hingedwalls 1210, 1211. Frame structure comprises a pair of slidable elements1220, 1221 and pair of slidable elements 1222, 1223. Each of the pair ofslidable elements 1220, 1221 and 1222, 1223 can slide together into aclosed position (FIGS. 13A and 13C) where there is a first distance d1between walls 1208 and 1209. The pairs of slidable element 1220, 1221and 1222, 1223 can slide apart into a second open or strained positionwhere there is a second distance d2 between the walls 1208, 1209 andwhere the distance d2 is greater than the distance d1 (as depicted inFIGS. 13B and 13A, respectively).

Hinged wall 1210 comprises first and second wall portions or segments1212 a, 1213 a that are movably, pivotally or hingedly connected to eachother by connector 1214 a, at a pivot point. Hinged wall 1211 comprisesa first and second wall segments 1212 b, 1213 b that are movably,pivotally or hingedly connected to each other by connector 1214 b at apivot point. Wall segments 1212 a and 1213 b are movably, pivotally orhingedly coupled respectively to opposite end sides 1208 a, 1208 b ofwall 11081208. Wall segments 1212 b and 1213 a are movably, pivotally orhingedly coupled respectively to opposite end sides 1209 b, 1209 a ofwall 1209. The walls 1208, 1209, 1210, 1211 are coupled to the framestructure 1202 to form a box-like structure with an opening (when in thestrained configuration) to provide access to a skin treatment device1240 attached across the bottom of the applicator to attachmentstructures 1203, 1204, 1206, 1207, 1246, 1247. This access allows a userto apply pressure to a skin treatment device as or after it is appliedto a skin surface, before removing the applicator 1200 from the skintreatment device. Alternatively, a pressure application device may becoupled to the applicator and actuable to provide pressure through theopening to a skin treatment device as or after it is being applied.

FIGS. 13A and 13C illustrate the applicator 1200 in a first, unstrainedposition. The frame structure 1202 is in an unstrained position whereslidable elements 1220, 1221 and slidable elements 1222, 1223 are in aclosed position. Wall segments 1212 a and 1213 a are pivoted to form av-shape collapsed into the box structure of the applicator 1200, andopposing wall segments 1212 b and 1213 b are pivoted to form a v-shapecollapsed into the box so that the distance between end walls is adistance d1. This position facilitates loading of an unstrained skintreatment device onto the applicator 1200.

After an unstrained device is loaded, the skin treatment device isstrained by applying opposing, outward forces to pulling rings 1218,1219, respectively attached to wall segments 1213 a, 1213 b. This forcestraightens side walls 1210, 1211 and pairs of sliding elements 1220,1221 and 1222, 1223 into an elongated or open position as shown in FIGS.54B and 54D, thus transferring a separation force to the skin treatmentdevice to strain the skin treatment device widthwise (relative to itsorientation and use on along a length of an incision). In othervariations, a single collapsible wall attached generally about themidpoints of the fixed configuration walls so only a single pullingforce is used to separate the fixed configuration walls.

When the device is in the strained position as shown in FIGS. 13B, and13D the wall segments 1212 a, 1213 a and 1212 b, 1213 b of walls 1210and 1211 are pivoted. As shown in FIGS. 13B and 13D, the side walls areover center or slightly hyper-extended or pivoted outward to provide astrain in a width wise direction with the force transferred to the skintreatment device through attachment structures 1203, 1204. Thus the skintreatment device may be strained in orthogonal directions or at leasttwo directions, i.e., the applicator provides a bi-directionally ormulti-directionally strained skin treatment device. The applicator 1100may be locked or maintained in a strained configuration by way of overcenter side walls. A latch or other stop such as a spring loaded pin mayengage one or more of inside surfaces of wall segments 1212 a, 1213 a,and 1212 h, 1213 b to maintain the applicator in its over center lockedposition.

FIGS. 13E to 13I illustrate other variations of a tensioning device,straining device or an applicator 1200 as previously described withrespect to FIGS. 13A to 13D, including an integrated stamper 1230. Thestamper 1230 is attached to the top of the handle, actuator ortensioning device 1201 of FIG. 13A with connectors 1235 that attach thedevice 1201 to the inside of the stamper side wall 1234. The stampercomprises a handle 1231 coupled to posts 1232 that extend through thetop wall 1238 of the stamper 1230. Posts 1232 are coupled to pressuremembers 1239 inside the stamper 1230. Prior to actuation, the pressuremembers 1239 are positioned within walls 1234, 1242, 1243, 1244 ofstamper 1230 above and the tensioning device 1201 as shown in FIG. 13G.Springs 1233 around the posts 1232 bias the handle 1231 in an upward(not stamping) configuration. Visibility openings 1248, 1249respectively in the handle 1231 and the top wall 1238 of the stamper1230 provide an opening through which the skin treatment device and/orwound can be seen, for positioning of the applicator 1200 in anappropriate location.

As shown in FIGS. 13E, and 13G, when the tensioning device 1201 is in anunstrained configuration, the length of its side walls 1210, 1211 areless than the length of the side walls 1242, 1244 of the stamper 1230.

In FIGS. 13F and 1311, the tensioning device 1201 is in a strainedconfiguration where the side walls 1242, 1244 of the stamper 1230 areapproximately that of the side walls 1210, 1211 of the tensioning device1201. In a strained configuration, an opening 1229 is provided in thetensioning device 1201 sized to receive the pressure members 1239therethrough. When a force is applied to the handle 1231 and thetensioning device 1201 is in a strained configuration, the pressuremembers 1239 extend down into and through the opening 1229 in theapplicator handle 1201, towards the skin treatment device (not shown),to apply a force to areas of the dressing where an adhesive interfacesthe skin of the subject. (FIG. 13I) Thus, where the adhesive is pressureactivated, the stamper 1230 applies a generally even pressure to theskin treatment device. All stampers described herein may be constructedof a foam or other compressible, conformable material which translatesthe force applied to handle 1231 to the skin treatment device (notshown). These other materials include silicones and styrenic blockcopolymers (e.g. KRATON®), in a solid or porous form.

As an option or alternative, the applicator 1200 may be provided withattachment structures 1236, 1237 that comprise a hook or loop structureof a hook and loop attachment mechanism, or any other attachmentstructure described herein. Likewise, side attachment structures 1203,1204 may also be a hook or loop structure or any other attachmentstructure.

As indicated previously, such assemblies and devices may also he used totreat skin grafts (including split-thickness and full-thickness grafts,xenografts, cadaveric graft, autologous grafts), skin flaps and skinsubstitutes, with or without the use of biomaterials or biodressings,either on top and/or below the graft/flap/substitute, or otherwise in atreatment site. In some embodiments, these assemblies and devices may beconfigured to apply a wound device that applies a uni-axial or bi-axial(or other multi-axial) compressive force to a treatment site. In somevariations, the axes of the straining force(s) acting upon the dressingvia the applicator, or the compressive forces acting upon the tissue viathe dressing, may be oriented such the dressing and/or applicator has orexerts a first directly applied force (i.e. not a subcomponent forcederived from one or more applied forces, or a summation force from twoor more other directly applied forces) and a second directly appliedforce that is not aligned, parallel or orthogonal to the first directlyapplied force. These forces may be further characterized as beingorthogonal to the orientations of the edge intersected by that force.The magnitudes of the straining force(s) directly applied by theapplicator to the dressing along each axis may be uniform ornon-uniform. Nominally, when the applicator is released from thedressing, the a portion of of the multi-axial forces is transferred tothe treatment site along each nominal axis. The amount of stress orstrain applied by the wound device may be pre-determined, as describedabove. For example, a circular pre-tensioned wound device 2300 may beapplied over a treatment site with a skin graft, flap or substitute2301, as schematically illustrated in FIG. 14A. In some variations, acircular pre-tensioned wound device may be applied over a wound orpre-closed (e.g., sutured) wound of a treatment site. The adhesiveperimeter 2302 of the wound device 2300 may circumscribe the skin graft2301, and may help ensure that compression is applied all around theskin region with the skin graft 2301. The wound device 2300 may beconfigured to apply radially inward compressive forces (represented byarrows 2304) after it is adhered to the skin and the tension isreleased. FIG. 14B depicts one variation of a rectangular wound device2310 that applies hi-axial compressive forces (represented by arrows2314) when applied to a skin region with a skin graft 2311. As with thecircular wound device 2300, the rectangular wound device 2310 may havean adhesive perimeter 2312. While circular and rectangular shaped wounddevices are depicted and described, it should be understood that wounddevices may have any desired shape (e.g., oval, triangle, trapezoid,square, any polygon, kidney-shaped, or irregularly shaped, etc.) and insome variations, may be shaped to accommodate the specific anatomicalcontours of the treatment site or custom-shaped to fit a particularwound of a particular individual.

Referring to FIGS. 15A to 15E, a tensioning device or radiallytensioning device 3000 is illustrated that may be used to apply a radialstrain to a circular, curved or arced portion of a dressing geometry byapplying a radially tensioning or straining force continuously or atdifferent points defining or along a curved or arced portion, perimeter,or edge of the dressing. The tensioning device may be used to evenlydistribute strain radially across a rounded dressing. According tovariations, an applied multi-axial strain may or may not be relativelyuniform in a radial direction from a center point of an arc, curve orcircle of a dressing.

A tensioning member 3000 comprises a straining structure 3006 and aframe 3001. The straining structure 3006 comprises a handle portion 3007and a plunger portion 3008. The frame 3001 comprises a support element3002 having an opening 3003 configured to receive the plunger portion3008 of the straining structure 3006, which is configured to fit withinand extend through the opening 3003 of the frame 3001. At least aportion of a cross section of the opening 3003 has an arced, curved orcircular shape which may be matched by the shape of the plunger portion3008.

A dressing assembly 3010 comprises a dressing 3011 removably coupled toan attachment sheet or attachment ring 3012. Prior to straining thedressing 3011, the attachment sheet or ring 3012 of the dressingassembly 3010 may be attached via an attachment structure 3013 to theframe 3001 over the circumference of the opening 3003 of the frame 3001.The attachment structure 3013 may include or be coupled to theattachment sheet or ring 3012. As shown in FIGS. 15D the attachmentsheet or ring 3012 may be attached to the frame 3001 by way of anadhesive 3014 such as an acrylic adhesive (e.g., 3M™ adhesive 9475LE).

The attachment structure or structures 3013 are positioned or located ina circular, arced or curved configuration about the attachment ring 3012so that the tensioning forces applied to the dressing assembly 3010 anddressing 3011 may applied radially with respect to the circular, arcedor curved shape.

In some variations the attachment structures may comprise one or moremechanisms or elements configured to facilitate separation, release,removal or detachment of the dressing from the applicator or tensioningdevice, other attachment elements, or other portions of the dressingassembly, including but not limited to the separation devices andmethods described herein. Release elements or releasable attachmentstructures may include but are not limited to pockets and tabs, hook andloop mechanism, hooks, angled bars, pivoting, rolling, rocking orsliding features associated with or coupled to attachment structures,adhesives, removable adhesives, adhesive tapes or other adhesivedevices, pegs, rip cords, towel bar configurations, sliding pins,friction locks, cam locks, vacuum or suction devices, snap connectors,carpet tack, press fit connections or other connections, levers,latches, locking members, spring members, for example, or othermechanisms such as cutters or rip cords or other structures or featuresto facilitate tearing, cutting or separation of attachment structures orelements perforated or otherwise severable structures, that permitremoval of dressing from the applicator , other portions of the dressingassembly and/or attachment structures, features, elements or portions.They may be self-releasing latches or spring members. They may beactuated when a pressure member is applied to a skin treatment deviceprior to removing the applicator. They may be manually actuated.

In FIG. 15C, the straining structure 3006 is shown just prior tostraining positioned, and facing the open side 3004 of the frame 3001with the dressing assembly 3010 attached to an opposing dressing side3005 of the frame 3001. At the dressing side 3005, the opening 3003 ofthe frame 3001 has a relatively larger diameter that matches or islarger than the diameter of the plunger portion 3008 of the strainingdevice 3006. At the open side 3004 of the opening 3003, a chamfer 3009may assist in guiding the plunger portion 3008 through the opening 3003.The plunger portion 3008 is slightly narrower that the smallest diameterof the opening in the frame while the handle portion 3007 is wider thatthe chamfer 3009 of the opening 3003, thus acting as a stop to limitstraining of a dressing to a predetermined amount when the handleportion 3007 abuts the open side 3004 of the frame 3001 (see FIG. 24E)

In FIG. 15E the tensioning device 3000 is shown straining the dressing3011. The plunger portion 3008 is inserted through the opening until thehandle portion 3007 abuts the open side 3004 of the frame 3001. Theplunger portion 3008 extrudes past the dressing surface 3005 to whichthe dressing 3011 is coupled or attached to thereby strain the dressing3011. The end 3008 a of the plunger portion 3008 extends past theopening side of the frame a predetermined distance d, thus straining thedressing 3011 a predetermined amount. The area of the end 3008 a of theplunger and the distance d determine the amount of strain applied to thedressing 3011.

As shown in FIGS. 15F and 15G a plurality of straining structures 3006 aand 3006 b constructed similarly to straining structure 3006, are showneach with different side wall lengths d1 and d2 respectively. The amountthe plunger portions extend past the dressing side 3005 of the frame3001 will determine the amount of strain imparted to the dressing. Eachof the straining structures 3006 a and 3006 b impart differentpredetermined amounts of strain to a dressing. According to variations,a straining device imparting a predetermined amount of strain to adressing may be selected from a plurality of straining devices eachdelivering a predetermined amount of strain. According to variations, akit comprising at least one dressing assembly and support and aplurality of straining structures each imparting different amounts ofpredetermined strained to a dressing may be provided.

Once the dressing 3011 is strained, the tensioning device 3000 may beused to apply the dressing 3011 to a subject.

The dressing 3011 includes a layer of a skin adhesive 3021 such as apressure sensitive adhesive e.g., as described herein, on an outwardlyfacing surface 3020 of the dressing 3011. An adhesive liner may bepositioned over the adhesive layer and removed prior to straining.

After application of the dressing 3011, the dressing 3011 may bedetached or separated from the tensioning device 3000 and the attachmentsheet or ring 3012 using a removal structure 3030. As shown in FIGS. 15Ato 15D the attachment sheet or ring 3012 includes a circumferentialperforation 3031 and pull tab 3032. The perforation 3031 is locatedcircumferentially inside of the attachment points where the adhesive3014 attaches the attachment sheet 3012 to the frame 3001. When the pulltab 3032 is pulled, the dressing 3011 is separated from the attachmentsheet 3012 and the tensioning device 3000 may then be removed leavingthe dressing 3011 on the skin. FIG. 15H illustrates a dressing 3011 thatis applied to a skin surface. A portion of the attachment ring 3012 maybe removed or may remain on the frame facing surface 3015 of thedressing 3011 after it has been applied to the skin.

in FIGS. 15A to 15F, the dressing, attachment sheet, attachmentstructures, frame, frame opening, and plunger portions are illustratedin a circular shape. Other round shapes or curved contours may be usedas well.

FIG. 15H illustrates a frame 3001 a and a dressing 3011 a releasablyattached to the frame 3001 a with attachment structures 3013 a, andpositioned over opening 3003 a in the frame 3001 a. The dressing 3011 ais relatively rectangular but may he of any desired size and shape thatmay or may not be different from the shape of the opening 3003 a and/orattachment structure(s) 3013 a. The opening 3003 a is circular, arced orcurved and is configured to receive a plunger of a straining structureto strain the dressing 3011 a. Attachment structure or structures 3013 amay or may not include an attachment sheet or attachment ring and maycomprise one or more attachment features. The attachment structure(s)3013 a are positioned about the opening 3003 a in a shape that generallymatches the shape of the opening, Different or selectable strainingstructures that may include a plunger, may be used to strain thedressing 3011 a as described herein.

FIG. 15I illustrates a frame 3001 b and a dressing 3011 b releasablyattached to the frame 3001 b with attachment structures 3013 h, andpositioned over opening 3003 b in the frame 3001 b. The dressing 3011 bis oval shaped but may be of any desired shape. The attachment structure3013 b shape generally matches or follows the shape of the edges of thedressing. Attachment structure or structures 3013 b may or may notinclude an attachment sheet or attachment ring and may comprise one ormore attachment features. The opening 3003 b is circular, arced orcurved but may be of any other desired shape. The opening 3003 b isconfigured to receive a plunger of a straining structure to strain thedressing 3011 b. Different or selectable straining structures that mayinclude a plunger, may be used to strain the dressing 3011 b asdescribed herein.

FIG. 15J illustrates a frame 3001 c and a dressing 3011 c releasablyattached to the frame 3001 c with attachment structures 3013 c, andpositioned over opening 3003 c in the frame 3001 c. The dressing 3011 cis relatively rectangular but may be of any desired size and shape thatmay or may not be different from the shape of the opening 3003 c and/orattachment structure(s) 3013 c. The opening 3003 c is irregularly shapedand is configured to receive a plunger of a straining structure tostrain the dressing 3011 c. Attachment structure or structures 3013 cmay or may not include an attachment sheet or attachment ring and maycomprises one or more attachment features. The attachment structure(s)3013 c are positioned about the opening 3003 c in a shape that generallymatches the shape of the opening 3003 c. Different or selectablestraining structures that may include a plunger, may be used to strainthe dressing 3011 c as described herein.

FIG. 15K illustrates a frame 3001 d and a dressing 3011 d releasablyattached to the frame 3001 d with attachment structures 3013 d, andpositioned over opening 3003 d in the frame 3001 d. The dressing 3011 dis irregularly shaped but may be of any desired shape. The attachmentstructure 3013 d shape generally matches or follows the shape of theedges of the dressing 3011 d. Attachment structure or structures 3013 dmay or may not include an attachment sheet or attachment ring and maycomprise one or more attachment features. The opening 3003 d isrectangular but may be of any other desired shape. The opening 3003 d isconfigured to receive a plunger of a straining structure to strain thedressing 3011 d. Different or selectable straining structures that mayinclude a plunger, may be used to strain the dressing 3011 d asdescribed herein.

FIG. 24L illustrates a frame 3001 e and a dressing 3011 e releasablyattached to the frame 3001 e with attachment structures 3013 e, andpositioned over opening 3003 e in the frame 3001 e. The dressing 3011 isirregularly shaped and includes a plurality of curved edges havingdifferent radii. While the attachment structures generally follow theshape of the dressing 3011 e, orthogonal distances between the dressinglateral edges and the attachment structure(s) may vary depending uponthe radius at a particular point. For example, a distance d1 is greaterat a location where the radius is shorter and a distance d2 is less at alocation where the radius is greater. The distance d1 is greater at alocation where the edge of the dressing curves in or is concave whilethe distance d2 is less at a location where the edge of the dress curesout or is convex. The opening 3003 e is configured to receive a plungerof a straining structure to strain the dressing 3011 e. Different orselectable straining structures that may include a plunger, may be usedto strain the dressing 3011 e as described herein.

While the frames in FIGS. 15H to 15L are schematically shown withrectangles, the shape of the frame may vary. Alternatively, the framemay comprise a circle, oval, egg, oblong, rectangle, square, triangle orother polygon, trapezoid, kidney bean, apple, clover, butterfly or pearshape and others mentioned elsewhere herein.

Referring to FIGS. 16A to 16G, a tensioning device or radiallytensioning device 4000 is illustrated that may be used to apply a radialstrain to variably curved or arced of a dressing geometry by applying aradially tensioning or straining force continuously or at differentpoints defining or along a curved or arced portions, perimeters, oredges of the dressing 4011. The tensioning device 4000 may be used toevenly distribute strain radially across the dressing. According tovariations, an applied multiaxial strain may or may not be relativelyuniform in a radial direction from center points of arcs or curves of adressing.

A tensioning member 4000 comprises a straining structure 4006 and aframe 4001. The straining structure 4006 comprises a handle portion 4007and a plunger portion 4008. The frame 4001 comprises a support element4002 having an opening 4003 configured to receive the plunger portion4008 of the straining structure 4006 which is configured to fit withinand extend through the opening 4003 of the frame 4001. A plurality ofportions 4041, 4042, 4043, 4044, 4045 of a cross section of the opening4003 have an arced or curved shape that may be matched by the shape ofthe plunger portion 4008. Each of a plurality of arced or curved sectionmay or may not have a different radius from the radii of the other ofthe plurality of arced or curved sections.

A dressing assembly 4010 comprises a dressing 4011 removably coupled toan attachment sheet or attachment ring 4012. Prior to straining thedressing 4011, the attachment sheet or ring 4012 of the dressingassembly 4010 may be attached via an attachment structure 4013 to theframe 4001 over the circumference of the opening 4003 of the frame 4001.The attachment structure 4013 may include or be coupled to theattachment sheet or ring 4012. As shown in FIG. 16D, the attachmentsheet or ring 4012 may be attached to the frame 4001 by way of anadhesive 4014 such as, e.g. an LDPE adhesive.

The attachment structure or structures 4013 are positioned or located ina shaped configuration about the attachment ring 4012 so that thetensioning forces applied to the dressing assembly 4010 and dressing4011 may be applied radially with respect to the arced or curved shapedportions.

In some variations the attachment structures may comprise one or moremechanisms or elements configured to facilitate separation, release,removal or detachment of the dressing from the applicator or tensioningdevice, other attachment elements, or other portions of the dressingassembly, including but not limited to the separation devices andmethods described herein. Release elements or releasable attachmentstructures may include but are not limited to pockets and tabs, hook andloop mechanism, hooks, angled bars, pivoting, rolling, rocking orsliding features associated with or coupled to attachment structures,adhesives, removable adhesives, adhesive tapes or other adhesivedevices, pegs, rip cords, towel bar configurations, sliding pins,friction locks, cam locks, vacuum or suction devices, snap connectors,carpet tack, press fit connections or other connections, levers,latches, locking members, spring members, for example, or othermechanisms such as cutters or rip cords or other structures or featuresto facilitate tearing, cutting or separation of attachment structures orelements perforated or otherwise severable structures, that permitremoval of dressing from the applicator, other portions of the dressingassembly and/or attachment structures, features, elements or portionsThey may be self-releasing latches or spring members. They may beactuated when a pressure member is applied to a skin treatment deviceprior to removing the applicator. They may be manually actuated.

In FIG. 16D, the straining structure 4006 is shown just prior tostraining, and positioned facing the open side 4004 of the frame 4001with the dressing assembly 4010 attached to an opposing dressing side4005 of the frame 4001. At the dressing side 4005, the opening 4003 ofthe frame 4001 has a relatively smaller diameter that matches or islarger than the diameter of the plunger portion 4008 of the strainingdevice 4006. At the open side 4004 of the opening 4003, a chamfer 4009may assist in guiding the plunger portion 4008 through the opening 4003.The plunger portion 4008 is slightly narrower that the smallest diameterof the opening in the frame while the handle portion 4007 is wider thatthe chamfer 4009 of the opening 4003, thus acting as a stop to limitstraining of a dressing to a predetermined amount When the handleportion 4007 abuts the open side 4004 of the frame 4001 (see FIG. 16F).Guide pins 4060 extend out of the open side 4004 of the frame 4001 andmay be inserted into corresponding guide holes 4070 of the strainingstructure 4006 in order to align the shapes of the frame 4001 andstraining structure 4006 as the dressing is strained.

In FIG. 16F, the tensioning device 4000 is shown straining the dressing4011. The plunger portion 4008 is inserted through the opening until thehandle portion 4007 abuts the open side 4004 of the frame 4001. Theplunger portion 4008 extrudes past the dressing surface 4005 to whichthe dressing 4011 is coupled or attached to thereby strain the dressing4011. The end 4008 a of the plunger portion 4008 extends past theopening side of the frame a predetermined distance d or amount thusstraining the dressing 4011 a predetermined amount. A locking mechanism4080 locks the straining structure 4006 in this position to the frame4001. The locking mechanism 4080 comprises a catch 4084 on the strainingstructure with a cam surface 4085. The catch 4084 engages a shelf 4086on the frame 4001 after the handle portion 4007 is positioned abuttingthe open side 4004 of the frame 4001.

The area of the end 4008 a of the plunger and the distance d determinethe amount of strain applied to the dressing 4011. The amount theplunger portions extend past the dressing side 4005 of the frame 4001will determine the amount of strain imparted to the dressing Accordingto variations, a straining device imparting a predetermined amount ofstrain to a dressing may be selected from a plurality of strainingdevices each delivering a predetermined amount of strain. According tovariations, a kit comprising at least one dressing assembly and supportand a plurality of straining structures each imparting different amountsof predetermined strained to a dressing may be provided.

Once the dressing 4011 is strained, the tensioning device 4000 may beused to apply the dressing 4011 to a subject.

The dressing 4011 includes a layer of a skin adhesive 4021 such as apressure sensitive adhesive e.g., as described herein, on an outwardlyfacing surface 4020 of the dressing 4011. An adhesive liner may bepositioned over the adhesive layer and removed prior to straining.

After application of the dressing 4011, the dressing 4011 may bedetached or separated from the tensioning device 4000 and the attachmentsheet or ring 4012 using a removal structure 4030. As shown in FIGS.16A, 16B and 16D the attachment sheet or ring 4012 includes acircumferential perforation 4031 and pull tab 4032. The perforation 4031is located circumferentially inside of the attachment points where theadhesive 4014 attaches the attachment sheet 4012 to the frame 4001. Whenthe pull tab 4032 is pulled, the dressing 4011 is separated from theattachment sheet 4012 and the tensioning device 4000 may then be removedleaving the dressing 4011 on the skin. FIG. 16G illustrates a dressing4011 that is applied to a skin surface. A portion of the attachment ring4012 may be removed or may remain on the frame facing surface 4015 ofthe dressing 4011 after it has been applied to the skin.

In FIGS. 16A to 16G, the dressing, attachment sheet, attachmentstructures, frame, frame opening, and plunger portions are illustratedin a kidney-shape where lateral edges have curved portions of varyingradius. Other shapes or curved contours may be used as well.

FIG. 17 illustrates a subject with non-linear incisions or wounds. Withfirst incisions 5000, a dressing such as, e.g., the dressing 4011 ofFIGS. 16A to 16G, may be used, for example, in breast reconstructionprocedures or other surgery where the dressing shape generally matchesan incision shape or contours of the subject's body. Wound 5100 has anon-linear and irregular shape. A dressing 5500 such as illustrated inFIG. 18 may be customized to match follow the shape of the wound 5100.The dressing 5500 may be strained using a tensioning device with amatching shape in a manner similar to that described with respect toFIGS. 15A to 15H and FIGS. 16A to 16G. Thus when aligned with and overthe wound 5100, the dressing may apply a generally perpendicularcompressive force inwardly towards the irregular line or shape of thewound 5100.

A center line of the dressing may be defined as generally originatingfrom the shape of or line(s) of the wound or incision. A matchingtensioning device may be constructed, for example, using 3-D printing tocustomize the shape of the tensioning device to match that of the customdressing 5500. The custom dressing may similarly be 3-D printed or cutin a desired shape. Accordingly the dressing 5500 may be strained toprovide perpendicular compressive strains to a center line 6000 of adressing 5500. In some variations, the dressing 5500 may be strainedsuch that the compressive strains to the center line 6000 is equidistantfrom edges using a line perpendicular to the center line 6000.

The dressing 4011 may alternatively be separated from the frame 4001using a cutter 4700 that extends from the handle 4007 throughcircumferential channel 4750 in the plunger 3008. (FIGS. 16B, 16H and16I) The cutters 4700 may be actuated from the handle so that theyextend out of the side walls 4900 of the plunger 4008 to cut thedressing. The channel openings 4725 are positioned below the end 4008 aof the plunger 4008 so that when the cutter 4700 is actuated it cuts ina planar direction substantially spaced from the skin of a subject.

The width of the dressing 4011 on an orthogonal line with respect to theedges of the dressing 4011 prior to cutting is 1 a. The length of thedressing 4011 on the orthogonal line after cutting at the cut line 4011a is 1 b. As shown in FIG. 16H, the total length of a strained dressingalong lines A-A is equal to the length of the sides walls 14, 13, 11, 12plus the length of the top wall 10. In this example, the length 14 isequal to opposing side wall length 12; the length 13 of the curvedportion of the side wall is equal to the length 11 of the opposingcurved portion of the side wall.

FIG. 16J illustrates a cross sectional view of a variation of a plunger5008. The total length of a strained dressing along a line orthogonal toits edges may be represented by the length of the side walls 14, 13, 11,12 plus the length of the top wall 10 of the plunger 5008 at thedepicted cross section. The total strain may be unevenly distributedacross the length based on the configuration of the side walls of theplunger 5008. In this example, the length 14 is longer than opposingside wall length 12; the length 13 of the curved portion of the sidewall is longer than the length 11 of the opposing curved portion of theside wall.

FIG. 16K illustrates a perspective view of a plunger 6008 that may beused with the frame 4001 and dressing assembly 4010. The length 15 ofthe side wall at the curved portion of the plunger 6008 is greater thanthe length 16 of the side wall at a convex curved portion of the plunger6008 for example, to counteract possible bunch if elastic dressingmaterial on the inside radius of the bend. The length 15 of the sidewall at the concave curved portion of the plunger 6008 is greater thanlength 17 of the side wall at a convex curved portion of the plunger6008.

One or more hemostatic or coagulative agents may be applied to, orotherwise integrated with dressing to help reduce bleeding. Potentialagents include chitosan, calcium-loaded zeolite, microfibrillarcollagen, cellulose, anhydrous aluminum sulfate, silver nitrate,potassium alum, titanium oxide, fibrinogen, epinephrine, calciumalginate, poly-N-acetyl glucosamine, thrombin, coagulation factor(s)(e.g. II, VII, VII, X, XIII, Von Willebrand factor), procoagulants (e.g.propyl gallate), antifibrinolytics (e.g. epsilon aminocaproic acid), andthe like. In some variations, the agents may be freeze-dried andintegrated. into the dressing and activated upon contact with blood orother fluid. In some further variations, an activating agent may beapplied to the dressing or the treatment site before the dressing isused on the subject. In still other examples, the hemostatic agent maybe applied separately and directly to the wound before application ofthe dressing, or after application to the dressing via a catheter ortube. The devices may also comprise one or more other agents that may beany suitable agent that may be useful in aiding in some aspect of thewound healing process. For example, the active agent may be apharmaceutical compound, a protein (e.g., a growth factor), a vitamin(e.g., vitamin E), or combinations thereof. Of course, the devices maycomprise more than one medicament or agents, and the devices may deliverone or more medicaments or agents. An example of such medicament mayinclude, but is not limited to various antibiotics (including but notlimited to cephalosporins, bactitracin, polyxyxin B sulfate, neomycin,polysporin), antiseptics (such as iodine solutions, silver sulfadiazine,chlorhexidine), antifungals (such as nystatin), antiproliferative agents(sirolimus, tacrolimus, zotarolimus, biolimus, paclitaxel), grow factors(such as VEGF) and other treatments (e.g. botulism toxin).

According to variations the various assemblies or devices describedherein may provide a temporary wound dressing that may be applied beforea wound is closed. The assembly may be configured to apply a dressing toa wound and to use the applicator to apply pressure to the wound beforeremoving or separating the applicator, tensioning device or dressingcarrier, base or support from the dressing. According to this variationwhich may be provided with any of the embodiments described below, theapplicator has sufficient rigidity to distribute a relatively even orfirm force to a wound by applying pressure to the applicator when and/orafter the dressing is applied to a wound. According to a variation, suchdressing may include a coagulation agent or other agent or medicament,for example as described herein. According to another variation, marginsas described herein, are provided on such a device between a dressingand edges used to manipulate the device.

While this invention has been particularly shown and described withreferences to embodiments thereof, it will be understood h those skilledin the art that various changes in form and details may be made thereinwithout departing from the scope of the invention. For all of theembodiments described above, the steps of the methods need not beperformed sequentially.

1. A method of straining a dressing, comprising: straining a firstdressing region along a first axis located in a first plane; straining asecond dressing region along a second axis located in a second planedifferent from the first plane, wherein the second dressing region iscoupled to the first dressing region; and applying the first dressingregion to a treatment site; and releasing at least some strain from thefirst dressing region.
 2. The method of claim 1, further comprisingseparating a third dressing region from the second dressing region torelieve at least some strain the first dressing region.
 3. The method ofclaim 1, wherein the second dressing region encloses the first dressingregion.
 4. The method of claim 2, wherein the third dressing regionencloses the second dressing region.
 5. The method of claim 1, whereinthe releasing at least some strain in the first dressing region releasessubstantially all of the strain in the second dressing region.
 6. Themethod of claim 1, wherein the straining of the first and seconddressing regions are pre-determined strains.
 7. The method of claim 1,wherein the straining of the first and second dressing regions occursprior to the applying the first dressing region to the treatment site.8. A method of straining a dressing, comprising: radially straining adressing to a pre-determined strain using an applicator, before applyingthe dressing to a treatment site; adhering the strained dressing to thetreatment site; and detaching the dressing from the applicator.
 9. Themethod of claim 8, wherein radially straining the dressing to apre-determined strain comprises radially straining the dressingout-of-plane before applying the dressing to the treatment site.
 10. Themethod of claim 8, wherein radially straining the dressing comprises:straining a first dressing region of the dressing along a first axislocated in a first plane; and straining a second dressing region of thedressing along a second axis located in a second plane different fromthe first plane.
 11. The method of claim 8, wherein the second dressingregion encloses the first dressing region.
 12. The method of claim 11,wherein detaching the dressing from the applicator comprises separatinga third dressing region from the second dressing region.
 13. The methodof claim 12, wherein the third dressing region encloses the seconddressing region.
 14. The method of claim 10, further comprisingreleasing at least some strain in the first dressing region upondetaching the dressing from the applicator.
 15. The method of claim 14,wherein releasing at least some strain the first dressing regionreleases substantially all of the strain in the second dressing region.